If a rock has a speed of 12 m/s as it hits the ground, from what height did it
fall, assuming its initial speed was zero? Its mass is 50 kg.
A. 600 m
B. 4.2 m
C. 12 m
D. 7.3 m

Answers

Answer 1

Answer:

To find the height the following formula should be used:  

v 2 = u 2 + 2aH

Explanation:

Assuming this occurs on earth,  a= 9.8 ms -2

 -2        2

12=0+2 x9.8 x H

144

_______ =H

2 x 9.8

H= 7.35m


Related Questions

pahelp po ako.

1. Which of the following terms refers to energy in motion?
A. kinetic energy C. potential energy
B. light energy D. thermal energy

2. Which of the following is a type of energy gained due to its position?
A. kinetic energy C. gravitational potential energy
B. light energy D. thermal energy

3. How do you get the total mechanical energy of an object in a closed system?
A. Get the sum of the initial and final kinetic energy.
B. Get the sum of the initial and final potential energy.
C. Get the sum of the kinetic energy and the potential energy.
D. Get the difference between the kinetic energy and the potential energy.

4. Which of the following is the best set up to observe the conservation of mechanical energy?
A. A cart rolling down a wooden ramp.
B. A wooden block falling in a vacuum.
C. A volleyball falling from a tall building.
D. a paper plane being launched from a tower.

5. A big rock was dropped from the third floor of a building. What happens to the kinetic energy of the ball as it falls?
A. The rock’s kinetic energy increases.
B. The rock’s kinetic energy decreases.
C. The rock’s kinetic energy remains the same.
D. The rock’s kinetic energy cannot be identified.

6. A heavy metallic ball was rolled up on a frictionless ramp. What happens to the gravitational potential energy of the ball as it rolls up the ramp?
A. The ball’s gravitational potential energy increases.
B. The ball’s gravitational potential energy decreases.
C. The ball’s gravitational potential energy remains the same.
D. The ball’s gravitational potential energy cannot be identified.


7. A 2kg ball is elevated up a building, how much is its potential energy 10m from the ground?
A. 5J C. 98J
B. 20J D. 196J

For items 8 to 10, refer to the illustration below. A ball is dropped at point W and travels along a frictionless path to reach point Z.
8. At which point does the ball has greatest gravitational potential energy?
A. W C. Y
B. X D. Z

9. At which point does the ball has greatest kinetic energy?
A. W C. Y
B. X D. Z

10. What happens to the total mechanical energy of the ball as it travels from point W to point Z?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.

For items 11 to 12, refer to the illustration below. A pendulum swings back and forth from its highest position to its lowest position and vice versa.

11. As a pendulum swings from its highest to lowest position, what happens to its gravitational potential energy and kinetic energy?
A. Both its GPE and KE increases.
B. Both its GPE and KE decreases.
C. Its GPE decreases but KE increases.
D. Its GPE increases but KE decreases.

12. What happens to the total mechanical energy of the bob as it swings back and forth if only force acting on it is the gravitational force?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.
Four ball of masses 0.5 kg, 1 kg, 2 kg, and 5 kg were dropped simultaneously on top of a building with the height of 20 m. Ignoring the air resistance, the four balls reach the ground at the same time.
13. Which of the following balls has the greatest gravitational potential energy on top of the building?
A. The ball with the mass of 5 kg.
B. The ball with the mass of 2 kg.
C. The ball with the mass of 0.5 kg.
D. All the balls have the same potential energy.
14. Which of the following balls has the least kinetic energy on top of the building?
A. The ball with the mass of 5kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same kinetic energy.

15. Which of the following balls has the greatest total mechanical energy?
A. The ball with the mass of 2kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same total mechanical energy

Answers

D bc thats sound like the only resonable answer

Clothes are flung to the sides of a round tub during the spin-cycle of a washing machine.If the tub's period of rotation is 0.2s and the tub's radius is 35cm,answer the related qestions below: (a)The frequency of roation (b)The circumference of rotation (c)The spinning of speed (d)The centripetal acceleration (e)The centripetal force of rotation if total mass rotated is 30kg (f)The power of washing machine​

Answers

Answer:

Explanation:

First I need to tell you that I used .20 s for the period of rotation instead of just .2, and I used 30.0 kg for the mass instead of just 30. The reason being that both those numbers as stated in the problem only have 1 significant digit and that's not generally enough to get the accuracy you're looking for. Adding a 0 to the ends of each of those numbers doesn't change the value of the numbers, only the number of sig fig's in each. Beginning with a:

a. [tex]f=\frac{1}{T}[/tex] so [tex]f=\frac{1}{.2}[/tex] and f = 5.0 Hz

b. The circumference is the distance around the outside of the washer's drum. We need to find that, but before we do, I'm going to state the radius in meters instead of cm. 35 cm = .35 m. Therefore,

C = 2(3.1415)(.35) so

C = d = 2.2 m

c. The speed of the washer is found in d = rt, where r is the rate and our velocity and d is the distance around the outside of the drum (circumference). Therefore,

2.2 = v(.20) so

v = 11 m/s

d. The centripetal acceleration has an equation

[tex]a_c=\frac{v^2}{r}[/tex] so

[tex]a_c=\frac{(11)^2}{.35}[/tex] and

[tex]a_c=\frac{121}{.35}[/tex] so

[tex]a_c=350\frac{m}{s^2}[/tex]

e. The centripetal force has an equation

[tex]F_c=\frac{mv^2}{r}[/tex] and

[tex]F_c=\frac{(30.0)(11)^2}{.35}[/tex] and

[tex]F_c=[/tex] 1.0 × 10⁴ N

f. The equation for Power is

[tex]P=\frac{W}{t}[/tex] where W is work and W = FΔx (force times displacement). Therefore,

[tex]P=\frac{(1.0*10^4)(2.2)}{.20}[/tex] so

P = 1.1 × 10⁵ Watts

The search for black holes involves searching for The search for black holes involves searching for Group of answer choices single stars that emit large amounts of X-rays. a stellar core greater than 3 solar masses large spherical regions from which no light is detected. pulsars with periods less than one millisecond. pulsars that are orbited by planets.

Answers

Answer:

Large spherical regions from which no light is detected

Explanation:

A black hole is an object that has an extremely high density such that it possesses very powerful gravitational force that prevents the escape of all objects including light from it, and consumes nearby objects.

Due to the power of the gravitational force of a black hole, at the center, objects are infinitesimally compressed resulting in the inapplicability of the concept of space and time and the location is known as a singularity

Therefore, the search for black holes involves searching for large spherical regions from which no light is detected.

What information does the period number give about an atom?​

Answers

Answer:All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.Explanation:

Answer:

It tells us the principle quantum shell in which the element lies in. In other words, it shows the total number of electron shells the atom has

what are MA and VR of a lever?​

Answers

Explanation:

Mechanical advantage (MA) = Load/Effort. Velocity ratio (VR) = distance effort moves/ distance load moves in the same time

Do the data for the first part of the experiment support or
refute the first hypothesis? Be sure to explain your
answer and include how the variables changed in the
first part of the experiment.
Mechanical equivalent of heat

Answers

Answer:

Sample Response: The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.

Explanation:

this the sample response from ED mechanical equivalent of heat lab.

Answer:

Sample response:

Explanation:

The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.

Compared to the inertia of a 1-kilogram mass, the inertia of a 4-kilogram mass is​

Answers

Explanation:

The inertia of a 4 kg mass is four times as great as a 1 kg mass.

The most powerful empire between the 1500s and 1600s was the __________ Empire.
A.
Ottoman
B.
Mauryan
C.
Roman
D.
Persian

Answers

Answer:

A

Explanation:

Answer:

Ottoman

Explanation:

siri told me after I asked


Sonny took 16 seconds to finish a 100-m race. What was
Sonny's average speed in the race

Answers

Speed = Distance/Time

=> Speed = 100m/16s

=> Speed = 6.25m/s

=> Speed = 6.25 ms^-1

4. An object is thrown from from the ground upward with an initial speed of 3.75 m/s. How long will the object be in the air before it lands on the ground?​

Answers

Answer:

Explanation:

There's an easy way to answer this and then an easier way. I'll do both since I'm not sure what you're doing this for: physics or calculus. Calculus is the easier way, btw.

Going with the physics version first, here's what we know:

a = -9.8 m/s/s

v₀ = 3.75 m/s

t = ??

That's not a whole lot...at least not enough to directly solve the problem. What we have to remember here is that at the max height of a parabolic path, the final velocity is 0. So we can add that to our info:

v = 0 m/s. Use the one-dimensional equation that utilizes all that info and allows us to solve for time:

v = v₀ +at and filling in:

0 = 3.75 + (-9.8)t and

-3.75 = -9.8t so

t = .38 seconds. This is how long it takes to get to its max height. Another thing we need to remember (which is why calculus is so much easier!) is that at the halfway point of a parabolic path (the max height), the object has traveled half the time it takes to make the whole trip. In other words, if .38 is how long it takes to go halfway, then 2(.38) is how long the whole trip takes:

2(.38) = .76 seconds. Now onto the calculus way:

The position function is

[tex]s(t)=-4.9t^2+3.75t[/tex] The first derivative of this is the velocity function and, knowing that when the velocity is 0, the time is halfway gone, we will find the velocity function and then set it equal to 0 and solve for t:

v(t) = -9.8t + 3.75 and

0 = -9.8t + 3.75 and

-3.75 = -9.8t so

t = ,38 and multiply that by 2 to find the time the whole trip took:

2(.38) = .76 seconds.

Capacitance (C) is measured in farads, where 1 farad is equivalent to 1 coulomb per volt. Resistance (R) is measured in ohms, and 1 ohm is equal to 1 volt per ampère. The coulomb is defined as the amount of charge passing when a current of 1 ampère flows for 1 second. What is the unit of RC expressed in its simplest form?

Answers

Ahhh ok so much better now I got a good day amp a Relationship was the day amp the

When fundamental units are combined, they result in derived units. RC (which means Resistance Capacitance) is a derived unit and its unit in the simplest form is Coulomb per Ampere (C/A)

Given that:

Capacitance (C) [tex]\to[/tex] Farads (f)

and

[tex]1f = 1\frac CV[/tex] ----- 1 farad = 1 capacitance per volt

Resistance (R) [tex]\to[/tex] Ohms [tex]\Omega[/tex]

[tex]1 \Omega = 1\frac{V}{A}[/tex]

The unit of RC is the product of the unit of R by the unit of C.

i.e.

[tex]RC = 1f \times 1\Omega[/tex]

Substitute [tex]1f = 1\frac CV[/tex]

[tex]RC = 1\frac CV \times 1\Omega[/tex]

Substitute [tex]1 \Omega = 1\frac{V}{A}[/tex]

[tex]RC = 1\frac CV \times 1\frac VA[/tex]

Cancel out volts (V)

[tex]RC = 1\frac CA[/tex]

[tex]\frac CA[/tex] means Coulomb per Ampere

Hence, the unit of RC is Coulomb per Ampere.

Read more about units at:

https://brainly.com/question/10167613

1.The distance moved by objects in a given interval of time can help us to decide which one is faster or slower. Do you agree with this statement?

Answers

Answer:

The rate of change of distance is defined as speed.

Explanation:

The speed is defined as the rate of change of distance.

Speed = distance/ time

When we know the distance and the time, we get the value of speed. So, e know that who is moving fast or slow.

hen a graph is pltted beteen the distance and time, the slope of the graph gives the value of speed. So, by checking the slopes, hoseslope ismore, the speed is more and thusit is moving faster.

So, i agree with the statement.  

A car moves with the speed of 40 km/hr for the first half and 60 km/hr
for Second half distance "What is the average distance of cars.​

Answers

Answer:

50 km/h

Explanation:

[tex](40 + 60) / 2[/tex]

-> [tex]50[/tex] (km/h)

Which forms of energy determine temperature: translational kinetic energy, rotational kinetic energy, vibrational kinetic energy, or all of these

Answers

oh this question seems to be difficult I don't think I can answer this

A glass tube in the shape of a letter J has the shorter limb sealed and the longer limb open. Mercury is poured into the tube until the levels in either limb is the same when the tube is vertical.In this position, the length of the air column in the sealed limb is 6.3cm.More mercury is then poured into the tube until the length of the trapped air column is 42cm.Calculate the difference in the levels of mercury in the limbs if a nearby mercury barometer reads 75.0cm and the reading of a nearby thermometer has not changed?​

Answers

Answer:

35.4 cm

Explanation:

We have that when the level of mercury on either limb is the same, the pressure of the trapped air, P₁ = Atmospheric pressure

Also the initial height of the mercury in the tube = The reading of the barometer = 75.0 cm

The initial length of the air column, l₁ = 6.3 cm

The final length of the air column, l₂ = 4.2 cm (The length is expected to decrease due to compression)

The volume, V = l × A

Where;

A = The cross sectional area of the tube

Therefore, the volume of the air column is directly proportional to the length of the air column

∴ V ∝ l

According to Boyles law, we have;

P₁·V₁ = P₂·V₂

Where;

P₁ = The initial pressure in the air column before more mercury is added

V₁ = The initial volume occupied by the air in the air column

P₂, and V₂ are the final pressure and volume of the air column respectively

Given that V = l·A, we can write;

P₁·l₁·A = P₂·l₂·A

P₂ = P₁·l₁·A/(l₂·A) = P₁·l₁/(l₂) = P₁ × 6.3/4.2 = 1.5·P₁

The pressure in the air column after more mercury is added, P₂ = 1.5 × P₁

P₁ = Atmospheric pressure, therefore;

The pressure in the air column after more mercury is added, P₂ = 1.5 × Atmospheric pressure

Pressure = h·ρ·g

Where;

ρ = The density of the substance

g = The acceleration due to gravity

h = The height of the column of the fluid

Given that the density and the gravitational force, can be taken as constant, we have that the pressure of the fluid is directly proportional to the height of the fluid column

Therefore, when the pressure doubles, the height of the fluid column doubles, and when the factor of increase is 1.5, we have;

The final level of the mercury, h₂ = 1.5·h₁ = 1.5×75 cm = 112.5 cm

The initial length of the closed end of the J tube, [tex]h_{closed1}[/tex] = 6.3 cm + 75 cm = 81.3 cm

The final length of the mercury in the closed end, [tex]h_{closed2}[/tex] = 81.3 cm - 4.2 cm = 77.1 cm

The difference in the level of mercury, Δh = h₂ - [tex]h_{closed2}[/tex]

∴ Δh = 112.5 cm - 77.1 cm = 35.4 cm

The difference in the levels of mercury in the limbs, Δh = 35.4 cm

Help me and I'll make u Brainliest and follow u

Answers

26. D. crushing the sugar cube and dissolving it in water.

27. A. atom

28. B. molecule

29. B. plum pudding model of Joseph John Thomson

30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.

31. D. protons and neutrons are relatively heavier than electrons.

How do the rocks in the mantle move?
A. They do not move.
B. They move in convection currents.
C. They flow like water.
D. They move on top of the crust.

Answers

Answer:

b. they move in convection currents.

Explanation:

i learned this in 4th grade

Why do scientists use science

Answers

Answer:

Firstly, science helps our understanding of the world around us. Everything we know about the universe, from how trees reproduce to what an atom is made up of, is the result of scientific research and experiment.

Scientists use the scientific method to collect measurable, experimental evidence in an experiment related to a term (often in the form of an if/then statement), the results aiming to support or differ a theory. In other words, scientific method helps scientists get accurate, repeatable results.

if an object is placed at the center of carvature of a convance mirror the image formed is called

Answers

Answer:

When the object is placed between centre of curvature and principal focus of a concave mirror the image formed is beyond C as shown in the figure and it is real, inverted and magnified.

Two planets are separated by a distance of 4.5x108 m. One of the planets has a mass of 2.1x1021 kg. The force of attraction between the planets is 5x1024 N. What is the mass of the other planet? (Be careful with your algebra!)

Answers

Answer:

The mass of the other planet is 7.23*10^(30) kg

Explanation:

For two objects of masses m₁ and m₂ respectively, separated by a distance r, the gravitational force between them is given by:

F = G*(m₁*m₂)/r^2

Where G = 6.67*10^(-11) m^3/(kg*s^2)

Here, we know that:

r = 4.5*10^8m

m₁ = 2.1*10^21 kg

F = 5*10^24 N

And we want to find the mass of the other planet, first, let's isolate m₂ in the force equation:

(F*r^2)/(G*m₁) = m₂

Now we can replace all the values that we know in the left side, and solve it:

m₂ =[(5*10^24 N)*( 4.5*10^8m)^2]/[6.67*10^(-11) m^3/(kg*s^2)*2.1*10^21 kg]

m₂ = 7.23*10^(30) kg

The mass of the other planet is 7.23*10^(30) kg

What is the meaning of the word "force"?

Answers

Answer:

Explanation:

The word force has a precise meaning. A force is exerted on one object by another. The idea of a force is not limited to living things or non-living things. All objects (living and non-living) can apply a force on or to another object also all objects (living and non living) can be affected by forces.

What kind of waves are present during an earthquake?​

Answers

Body Waves - Primary (P) & Secondary (S) Waves.
Surface Waves - Rayleigh & Love Waves.

Answer:

There are four main types of earthquake waves:

P-waves S-waves (which are body waves), Rayleigh waves Love waves (which are surface waves).

HOPE IT HELPS!!

Question 5 of 10
A 15 N force is applied to an object, which then accelerates at 5.0 m/s2. What
is the mass of the object?
A. 10 kg
B. 20 kg
C. 75 kg
D. 3.0 kg

Answers

Hi there!

[tex]\large\boxed{D. \text{ } 3.0 kg}}[/tex]

Use the following equation to solve:

F = ma, where:

F = Force (N)

m = mass (kg)

a = acceleration (m/s²)

Thus:

15 = 5m

15/5 = m

mass = 3 kg

D is the correct answer

Find the transformation matrix that rotates a rectangular coordinate system through an angle of 60 about axes equal angels with original three coordinate axes

Answers

Answer:

  [tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]

Explanation:

To find the matrix, let's decompose the vectors, the rotated angle is (-60C) for the prime system

          x ’= x cos (-60)

          y ’= y sin (-60)

we use

          cos 60 = cos (-60)

          sin 60 = - sin (-60)

we substitute

          x ’= x cos 60

          y ’= - y sin 60

the transformation system is

         [tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right] = \left[\begin{array}{ccc}cos 60&0\\0&-sin60\end{array}\right] \ \left[\begin{array}{ccc}x\\y\end{array}\right][/tex]x '

the transformation matrix is

       [tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]

What is the net force on a remote controlled airplane if a force of 57.6N is applied West and a force of 95.7N is applied South?

Answers

Answer:

112 N at 239°

Explanation:

Applying,

Pythagoras theorem,

a² = b²+c².................. Equation 1

Where a = net force

From the question,

Given: b = 57.6 N, c = 95.7 N

Substitute into equation 1

a² = 57.6²+95.7²

a² = 3317.76+9158.49

a² = 12476.25

a = √12476.25

a = 111.7 N

a ≈ 112 N

Then the direction is given as

∅ = tan⁻¹(c/b)........... Equation 2

∅ = tan⁻¹(95.7/57.6)

∅ = tan⁻¹(1.66)

∅ = 58.9°

∅ ≈ 59°

Since the angle is in the third quadrant,

∅' = 59+180

∅ = 239°

Hence the right answer is

112 N at 239°

Un auto que acelera a razón de 2 m/S^2 ; Si para cierto tramo se observa que logra triplicar su rapidez en 6 s. ¿Cuál fue su rapidez al final de estos 6 segundos?

Answers

Answer:

12m/s

Explanation:

Using the equation of  motion

v = u + at

Given that

u = 0m/s

a = 2m/s²

time t = 6s

Substitute the given values into the expression

v = 0 + 2(6)

v = 0+12

v = 12m/s

Hence the required velocity is 12m/s

Select the correct answer. The motion of a car on a position-time graph is represented with a horizontal line. What does this indicate about the car’s motion? A. It’s not moving. B. It’s moving at a constant speed. C. It’s moving at a constant velocity. D. It’s speeding up.

Answers

If the car's motion appears as a horizontal line on a position-time graph, it shows that as time changes, the car's position doesn't change.

This is just a complicated way to say that the car is not moving. (A)

Answer: It's not moving.

Explanation:

I got it correct on edmentum.

A student sects a leaf of length 7.2 cm to draw. Her drawing is 28.8 cm in length. What is the magnification of the drawing?
a) x4
b) x207.36
c) x0.25
d) x36

Answers

Answer:

A) x4

Explanation:

Magnification is equal to image size divided by the actual size, or M = I/A.

The image size is the student's drawing, which is 28.8 cm, and the actual size is 7.2 cm. Divide them, and cancel out the units, and you should get:

28.8 cm/7.2 cm = 4

a.in which portion of the curve,
1. is the velocity uniform.
2.is the velocity increasing.
3.is velocity decreasing.
4.is acceleration zero.

B. at which point does the body start to move and stop.
________________________


I will mark as brainlist​

Answers

Answer:

the answer is 4 acceleration is 0

Explanation:

this is because when parallel line is drawn through x axis the velocity will bw uniform

plz brainliest

Answer all these questions

What type of waves can only travel through a medium?
What is pitch?
What is the relationship between amplitude and volume?
How does the type of medium affect a sound wave?
Describe the relationship between frequency and wavelength.

Answers

Answer:

mechanical waves,

.

the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone.

.

If the amplitude increases the volume increases and vice versa.

.

The type of medium affects a sound wave as sound travels with the help of the vibration in particles.

.

The higher the frequency, the shorter the wavelength.

Explanation:

Answer:

1 . Soundwave

2. pitch are sounds that are high or low corresponding and according to a certain frequency measured in Hertz

3. volume is the increase in sound or decrease in sound how loud or soft something is while amplitude is strength of sound

4. frequency is measured in Hertz one wave per second and wavelength is distance between corresponding points of two recurring and consecutive sound waves

Other Questions
Which of the following could be classified as a molecular element?Question 1 options:kryptonlithiumnitrogencalciumAll four are classified as molecular elements. HELPPP SOMEONE PLEASSSSE Which component of weight is cause for S.H.M of bob simple pendulum Contamination is when substances get into food, making it unsafe. Suppose there is a simple one good economy that only produces spinning rims. In 2015, the economy was able to produce 1 million sets of spinning rims at an amazing price of $500 per set. In 2016, the economy was able to produce 1 million sets of spinning rims at a price of $1,000 per set. By what amount did real GDP increase between 2015 and 2016 in the simple one good economy The Last Leaf:How does the symbol help to convey the theme? Define Rise over Run and Define Slope. Please help me I need it asap! A car moving east at a velocity of 16.0 m/s collides with a stationary truck with exactly twice the mass. If the two vehicles lock together, calculate the velocity of their combined mass immediately after collision why should we support and love our classmates ? In the figure below, AE | BD. What is the value of x? The father in an ancient Roman family was legally allowed to crivez quatre verbes pronominaux * What is the next step after gathering information when making smart food choices? please give full solutions 8281 Write a main function that declares an array of 100 ints. Fill the array with random values between 1 and 100.Calculate the average of the values in the array. Output the average. Two adjacent angles of a parallelogram are congruent. What is the measure ofeach? What is dramatic irony? One paragraph Summary on Challenges of Development Calculate the Experimental Molar Volume in L/mol of the Hydrogen gas, H2, if the volume of H2 at STP is 52.8 mL and the mass of Magnesium metal, Mg, used in the experiment is 0.055 g. True or false The atomic number of an element is always more than the mass number of that elemenT