Answer: 392N
Explanation: W=mg
W= 40x9.8
= 392N
Answer:
[tex]\large \boxed{\sf 392.4 \ N}[/tex]
Explanation:
[tex]\sf Weight \ (N) =mass \ (kg) \times acceleration \ of \ gravity \ (m/s^2)[/tex]
[tex]W=mg[/tex]
[tex]W=40 \times 9.81[/tex]
[tex]W= 392.4[/tex]
Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time what should she do
Answer:
C. Walk four times per week
Explanation:
If she wants to increase her time then, she has to walk four times per week.
What is speed?The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.
The mathematical expression for speed is given by
speed = total distance /Total time
As given in the problem Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She must walk four times a week if she wants to extend her time.
Thus, the correct answer is option C.
Learn more about speed from here, refer to the link;
brainly.com/question/7359669
#SPJ2
The question is incomplete, the complete question is,
Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time. What should she do?
A. Walk at 4.5 miles per hour.
B. Walk for 50 minutes.
C. Walk four times per week.
D. Walk up and down more hills.
WILLL GIVE 5 STARS BRAINIEST AND THANKS AND 20 POINTS EACH ANSWER!!!!
A diver performs a dive from a 10 m-platform. She
jumps vertically upwards at 3 m s initially.
Find the time she takes to reach the water surface
Answer:
The time she takes to reach the water from when she jumps off the platform is 1.71 s
Explanation:
According to the equations of motion, we have;
v = u - g·t
v² = u² - 2·g·s
s₁ = u₁·t₁ + 1/2·g₁·t₁²
The given parameters are;
The height of the platform (assumption: above the water) = 10 m
The velocity with which she jumps, u = 3 m/s
The acceleration due to gravity, g = 9.81 m/s²
The height to which she jumps, s, is found as follows;
v² = u² - 2·g·s
At maximum height, v = 0, which gives;
0 = 3² - 2×9.81×s
2×9.81×s = 3² = 9
s = 9/(2×9.81) = 0.4587 m
s = 0.4587 m
The time to maximum height, t, is found as follows;
v = u - g·t
0 = 3 - 9.81×t
9.81×t = 3
t = 3/9.81 = 0.3058 s
The total distance, s₁ from maximum height to the water surface = s + 10 = 0.4587 + 10 = 10.4587 m = 10.46 m
The time to reach the water from maximum height, t₁, is found as follows;
s₁ = u₁·t₁ + 1/2·g₁·t₁²
Where;
s₁ = The total distance from maximum height to the water surface = 10.46 m
u₁ = The initial velocity, this time from the maximum height = 0 m/s
g₁ = The acceleration due to gravity, g (positive this time as the diver is accelerating down) = 9.81 m/s²
t₁ = The time to reach the water from maximum height
Substituting the values gives;
s₁ = u₁·t₁ + 1/2·g₁·t₁²
10.46 = 0·t₁ + 1/2·9.81·t₁²
t₁²= 10.46/(1/2×9.81) = 2.13 s²
t₁ = √2.13 = 1.46 s
Total time = t₁ + t = 1.46 + 0.3058 = 1.7066 ≈ 1.71 s.
Therefore, the time she takes to reach the water from when she jumps off the platform = 1.71 s.
Calculate the average kinetic energy of molecules of a gas at a temperature of 18 ° C
Answer:
6.0×10⁻²¹ J
Explanation:
KE = 3/2 kT,
where KE is average kinetic energy per molecule,
k is the Boltzmann constant,
and T is absolute temperature.
KE = 3/2 (1.38×10⁻²³ J/K) (18 + 273.15) K
KE = 6.0×10⁻²¹ J
Answer:
The answer is 6.0×10⁻²¹ J , because KE = 3/2 kT, where KE is average kinetic energy per molecule, k is the Boltzmann constant, and T is the absolute temperature.
KE = 3/2 (1.38×10⁻²³ J/K) (18 + 273.15) K
KE = 6.0×10⁻²¹ J
A disk-shaped dough is initially spinning at 2 rotations per second (1 rotation = 360°). As time goes on, it slowly deforms, and is now spinning at a different angular speed. The dough changed radius from 16 cm to 17 cm, and its mass remained constant throughout. What is its final angular speed in degrees/s?
Answer:
10.44° per sec
Explanation:
Initial angular speed N = 2 rotations per minute
converting to rad/s ω = 2πN/60 = (2 x 3.142 x 2)/60 = 0.21 rad/s
the initial radius of the disk = 16 cm = 0.16 m
final radius = 17 cm = 0.17 m
Angular momentum = [tex]I[/tex]ω
where [tex]I[/tex] = rotational inertia = mass x [tex]radius^{2}[/tex]
ω = angular speed
For the initial case
[tex]I[/tex] = m x [tex]0.16^{2}[/tex] = 0.0256m
Angular momentum = 0.0256m x 0.21 = 0.0054m
For second case
[tex]I[/tex] = m x [tex]0.17^{2}[/tex] = 0.0289m
Angular momentum = 0.0289m x ω = 0.0289mω
For conservation of rotational momentum, initial angular momentum must be equal to the final angular momentum
0.0054m = 0.0289mω
m cancels out, we have
0.0054 = 0.0289ω
ω = 0.187 rad/s
converting back to rpm, we have
N = 0.187/2π = 0.029 rotations per sec
0.029 x 360 = 10.44° per sec
John owns a used 2003 mustang Mach 1, he spots a news crew with a bunch of people what should he do? A) Rev his engine at the highest RPM B) Do a burnout C) Drive near the Crowd and drop a gear and hurl into the crowd D) ALL OF THE ABOVE
Each of the three choices is tasteless, exhibitionist, juvenile, and dangerous. John should do none of them.
Encountering a news crew, there's no reason for John to call attention to himself in a childish way, or interfere with their work in any way.
What he should do is:
==> Slow down
==> Pass the scene cautiously
==> Resume his normal, legal speed quietly, in case the crew happens to be recording audio at the moment.
Mysteriously, this course of action is nowhere to be found among the choices listed.
Answer:
all three options :)
Explanation:
cuz merica
answer answer answer it it it
Answer:
Parachutes
Explanation:
Your parachute allows you to descend more slowly because it lowers terminal velocity by increasing your air resistance. Most parachutes are designed to create a large amount of drag and allow you to land at a safe, low speed.
HOPE THIS HELPS!!!
MARK IT AS BRAINLIEST !!!! ( the crown icon sometimes )
Which statement describes one feature of Rutherford's model of the atom?
O The atom is mostly empty space.
O The atom cannot be divided into smaller particles.
O Electron clouds are regions where electrons are likely to be found.
O The electrons are located within the positive material of the nucleus.
Answer:
The atom is mostly empty space.
Explanation:
Ernest Rutherford in the year 1911 developed a model of an atom. In his model the atom was shown that the atom is mostly empty spaces composed of negative electrons which orbits round a positive nucleus just like planets revolving round the sun.
Rutherford came up with this model by performing experiments in 1909 which involves the scattering of alpha particles on a thin gold foil. From this experiments he came up with his model.
Answer:
A!
Explanation:
The atom is mostly empty space.
3) An earth moving machine uses diesel oil, which when burnt will produce 3.0x10 9 J of energy. The work performed by the machine is 2.7x 10 8 J. What is the efficiency of the machine?
Answer:
The answer is below
Explanation:
The efficiency of a machine is the ratio of its output to its input. The efficiency shows how effective the machine by the way it converts the input energy into work. The higher the efficiency of the machine the more effective it is. The efficiency is usually less than 1.
Given that the machine uses diesel oil (input) that can produce 3.0 x 10⁹ J of energy while the work performed by the machine (output) is 2.7 x 10⁸ J. The efficiency is given as:
Efficiency = output / input = 2.7 x 10⁸ J / 3.0 x 10⁹ J = 0.09 = 9%
This means that the machine is not effective because of its low efficiency
Match words at the left to the correct blanks in the sentences on the right. Not all words will be used.1. The energy that drives the expansion of a star into a subgiant or red giant comes from HYDROGEN SHELL FUSION2. Stars with mass greater than about 8 solar masses are considered HIGH-MASS STARS3. The final stage of core fusion in a low-mass star is HELIUM FUSION4. Stars that are fusing hydrogen in their cores are MAIN-SEQUENCE STARS5. When it dies, a high-mass star explodes as a SUPERNOVA6. A star that is expanding (into a subgiant and then a giant) has a(n) INERT HELIUM CORE7. When it dies, a low-mass star expels a PLANETARY NEBULA8. Stars with masses less than about two solar masses are considered LOW-MASS STARS
Answer:
In what way is iron unique among the elements?
It has the lowest mass per nuclear particle.
Match words at the left to the correct blanks in the sentences on the right. Not all words will be used.
-The energy that drives the expansion of a star into a subgiant or red giant comes from HYDROGEN SHELL FUSION
-Stars with mass greater than about 8 solar masses are considered HIGH-MASS STARS
-The final stage of core fusion in a low-mass star is HELIUM FUSION
-Stars that are fusing hydrogen in their cores are MAIN-SEQUENCE STARS
-When it dies, a high-mass star explodes as a SUPERNOVA
-A star that is expanding (into a subgiant and then a giant) has a(n) INERT HELIUM CORE
-When it dies, a low-mass star expels a PLANETARY NEBULA
-Stars with masses less than about two solar masses are considered LOW-MASS STARS
A stationary siren creates an 894 Hz
sound. When a motorcyclist is driving
toward it, she hears a 926 Hz sound
How fast is she driving?
(Speed of sound = 343 m/s)
(Unit = m/s)
Answer:
12.3 m/s
Explanation:
The Doppler equation describes how sound frequency depends on relative velocities:
fr = fs (c + vr)/(c + vs),
where fr is the frequency heard by the receiver,
fs is the frequency emitted at the source,
c is the speed of sound,
vr is the velocity of the receiver,
and vs is the velocity of the source.
Note: vr is positive if the receiver is moving towards the source, negative if away.
Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.
Given:
fs = 894 Hz
fr = 926 Hz
c = 343 m/s
vs = 0 m/s
Find: vr
926 = 894 (343 + vr) / (343 + 0)
vr = 12.3
The speed of the car is 12.3 m/s.
Question 2 of 10
Which of the following is an Sl unit?
A. Foot
B. Inch
C. Meter
D. Mile
SUBMIT
Answer:
C. Meter
Explanation:
The International System of Unit (SI) is gotten from the french word Systeme international is a modern form of metric measurement. It is the system of measurement that is universally accepted. It is from this SI units that all other system of units are derived. There are seven basic SI units which are:
1) Length in Meter (m)
2) Time in Seconds (s)
3) Amount of Substance in mole (m)
4) Electric current in ampere (A)
5) Temperature in kelvin (k)
6) Luminous intensity in candela (cd)
7) Mass in kilogram (kg)
The particles of a GAS within a closed container will collide with the container walls, exerting a FORCE. The force per unit of AREA is known as what?
Answer:
Pressure
Explanation:
One of the theories propounded by the Kinetic molecular theory, and which also provides an explanation of the several gas laws, is the statement that the gas molecules in a container, travel in straight lines and are in constant collision with themselves and the walls of the container, thus exerting force. This force is the pressure which is defined as the force per unit area.
There is no loss of energy in the collisions involving the gas molecules and that is why their movement can be described as elastic. The descriptions of the behavior of gas molecules in the Kinetic Molecular Theory, give rise to Charles law, Boyle's Law, Avogadro's Laws, Dalton's Law, and Amonton's Law.
Answer:
The pressure
Explanation:
Molecules of gases are constantly in motion, colliding with the walls of their container. This constant collision impacts force on the walls of the container, which depends on the speed with which the molecules are moving. The speed with which these molecules travel depends on the average kinetic energy of the molecules, which is proportional to the temperature.
This force when exerted per unit area is the pressure the gases exert on the walls of the container.
The ways to measure the mass and volume of irregular object
Answer:
When we have irregular objects, it may become very hard to calculate the volume of the object, as we actually can not use any simple equation to find it.
The mass is less tricky, just find a scale and wheight it, now we know the mass of the irregular object.
One way to measure the volume of the object is using water... how we do it?
Get some recipient with water, measure the height of the water.
Introduce your object into the water and totally submerge it, now the level of the water will rise. This is because as you introduce the object under the water, you are displacing up a given volume of water that has the same volume as the irregular object.
Now that you know the height of the water before and after you put your object, you can easily calculate the volume of water displaced, and that will be the volume of the object (the tricky part may be totally submerging the object if, for example, is wood and it floats, here you can use a thin wire to push it down but it will affect a little bit the measures.)
A gauge is reading the pressure at the bottom of a river, at a depth of 6 m. Would the reading be greater or smaller than the reading at the bottom of a lake at the same depth? You must provide a clear explanation for full credit.
Answer:
The pressure at the bottom of the river is less than that at the bottom of the lake.
Explanation:
From Bernoulli's equation, the pressure difference is given by
ΔP = ρgΔh + ρ(v₂² - v₁²)/2 where ρ = density of water, g = acceleration due to gravity, Δh = depth, v₁ = velocity at top, v₂ = velocity at bottom
For the lake, v₁ = v₂, since the velocity at the top and bottom are the same. So,
ΔP₁ = ρgΔh + ρ(v₁² - v₁²)/2 = ρgΔh + 0 = ρgΔh
P₂ - P₁ = ρgΔh
P₂ = P₁ + ρgΔh
For the river, v₁ < v₂, since the velocity at the top of the river is greater than at the bottom.
So,
ΔP₂ = ρgΔh + ρ(v₂² - v₁²)/2.
Since v₁ < v₂, ρ(v₂² - v₁²)/2 will be negative,
So,
ΔP₂ = ρgΔh - ρ(v₂² - v₁²)/2.
Since ρ(v₂² - v₁²)/2 is negative, making ΔP less than that in the lake.
So, ΔP₂ = ΔP₁ - ρ(v₂² - v₁²)/2.
ΔP₂ = P₃ - P₁
P₃ - P₁ = P₂ - P₁ - ρ(v₂² - v₁²)/2.
P₃ = P₂ - ρ(v₂² - v₁²)/2.
where P₃ = pressure at bottom of the river and P₂ = pressure at bottom of the lake and P₁ = atmospheric pressure at top of river and lake respectively.
Since the factor ρ(v₂² - v₁²)/2 is removed from the pressure at the bottom of the lake, the pressure at the bottom of the river is therefore less than that at the bottom of the lake.
Which two possible explanations does the video give for why white light changes into colored light? Color is an impurity added to white light by the prism. Color is present in the materials on which white light shines. White light contains seven colors, which are separated by the prism. White light reacts with chemicals in the air to produce seven colors.
Answer:
White light contains seven colors, which are separated by the prism.
White light reacts with chemicals in the air to produce seven colors.
Explanation:
It was first observed by Sir Issac Newton, that when white light is passed through a prism, an elongated, coloured patch of light is obtained on a screen placed behind the prism. The seven colours obtained constitute the spectrum of white light.
In nature, white light is separated into its constituent wavelengths when white light interacts with substances in the atmosphere.
Answer:
The correct answer is “color is an impurity added to white light by the prism.”
and
“White light contains seven colors, which are separated by the prism
Explanation:
Select the correct answer. Rita is a registered dietician. What does her work entail? A. prescribing medication for clients B. cooking healthy meals for students C. demonstrating how to use gym equipment D. making recommendations for healthy eating habits
Answer:
D
Explanation:
The answer is D because:
A) Only doctors are allowed to prescribe medications.
B) Rita is not a chef/cook.
C) Rita is not a personal trainer
D) The job of a dietican is to provide reccomendations to their clients in order for them to implement a healthy lifestyle via consuming what is best for them.
Hope this helps :)
Answer:
D.) Making recommendations for healthy eating habits
Explanation: PLATO :)))
White light is spread out into its spectral components by a diffraction grating. If the grating has 1,970 grooves per centimeter, at what angle (in degrees) does red light of wavelength 640 nm appear in first order? (Assume that the light is incident normally on the gratings.)
Answer;
7.238°
Explanation
From question we know that the grating has 1,970 grooves per centimeter, we can convert to from (cm) to (nm) for unit consistency
The slit separation is expressed below
d=1cm/1970
d=0.0005076
=5076nm
Then the angle (in degrees) that the red light of wavelength 640 nm appear in first order can be calculated using expression below
Sin(x)= mλ/d
Where λ= wavelength=640 nm
d=slit separation
Sin(x)= mλ/d
Sin(x)=(1×640)/5076
=0.126
sin-1(0.126)
X= 7.238°
Therefore,the angle (in degrees) that the red light of wavelength 640 nm appear in first order is 7.238°
Hi please may someone help me especially on the sketch part.
An object falls from a hovering helicopter and hits the ground at a speed of 30 m/s. How long does it take the object to reach the ground and how far does it fall? Sketch a velocity-time graph for the object (ignore air resistance).
Ignoring the air resistance it will take about 3 seconds for the object to reach the ground.We know that the acceleration due to gravity is 10m/s2.
We also know that the final velocity is 30 m/s while the initial velocity is 0 m/s
we can use the formulae for acceleration to calculate the time taken/
(final - initial velocity)/timetaken=10
(30-0)/timetaken=10
timetaken =30/10=3 seconds
an object is +2 m from the reference point. the object starts from rest it travels for 3 seconds and has a final position of -16 m. what is the acceleration of the object?
Answer:
Solution
Given:
initial velocity (u)=0m/s (because an object
starts from the rest)
time (t)=3sec
diatance travelled(s)=14m(16-2=14)
acceleration (a)=?
Now,
According to the formula
s=ut+1/2at^2
or,14 =0×3+1/2×a×3^2
or, 14=0+a/2×9
or, 14=9a/2
or, 9a=28
or, a=28/9
or, a=3.1 m/s^2
Therefore, the acceleration of the object is 3.1m/s^2 ans.
Solve for angles A-D
(02.10 LC)
Which American sport stems from a combination of the British sports rugby and soccer?
Baseball
Basketball
Tennis
Football
Question 2 Multiple Choice Worth 5 points)
Answer:
football
Explanation:
I took the 2.10 quiz and got it wrong so it must be football
A machine can never be 100% efficient because some work is always lost due to which factor? friction gravity static input force
Explanation:
Hi,
The answer is friction.
There is almost no machine which are not affected by friction. It losts some work due to friction while working.
Hope it helps..
Answer:
friction
Explanation:
the other options dont effect efficiency
A central air-conditioner uses 3500W of electricity. If electricity costs $0.087/kW*h. calculate how much it would cost to operate the air-conditioner 24 hours a day for 4 months (120 days).
Answer:
$876.96
Explanation:
The energy used is:
3500 W × (24 hr/day) × (120 day) × (1 kW / 1000 W) = 10,080 kWh.
So the cost is:
10,080 kWh × ($0.087 / kWh) = $876.96
what is the function of eye lens of the human eye
Answer:
Lens of the human Eye is a important and one of that most complex sense organ.
Explanation:
Lens of the human eye it helps that in visualizing light and color perception and objects , glance on the human eye structure and function.
Sense organs are much pretty similar to the camera they help us see the objects clear.
A human eye is the 2.3 cm in diameter and all filled some fluid, and there are following parts in eye:- cornea, Retina , Lens ,Pupil , optic nerves.
cornea :- the cornea is the first transparent part of is called cornea, enters the light through the cornea.
Retina :-it is light sensitive layer that consists of nerve cells,then transmitted to the brain through nerves.
Lens:- behind the pupil there is a transparent structure called lens,it shape focus light on the retina.
Pupil:-it control the value of light that enters the human eye.
Optic nerves is are the two types :- (1) cones (2) Rods .
Answer:
It causes Light Rays to converge on the retina
Explanation:
I took the K12 Test
Question 1 (2 points)
(01.01 LC)
Which of the following is a characteristic of science? (2 points)
QU
Reproducible by other scientists
Ob
The personal opinion of the scientist
С
Using variable conditions for each test
d
Including only the data that supports a hypothesis
Answer:
Reproducible by other scientists
Explanation:
I just took the test
if you ran 15 km/hr for 2.5 hours, how much distance would you cover?
Answer: 37.5 km
Explanation:
The question is that
If you ran 15 km/hr for 2.5 hours, how much distance would you cover ?
Where
Speed = 15 km/ hr
Time = 2.5 hours
Using the formula for speed.
Speed = distance/time
Substitute speed and time into the formula
15 = distance/ 2.5
Make distance the subject of formula by cross multiplying.
Distance = 15 × 2.5
Distance = 37.5 km.
Identifying Energy Transformations
What is one energy transformation that is taking place when a plant is growing?
radiant energy to thermal energy
thermal energy to nuclear energy
O chemical energy to thermal energy
O radiant energy to chemical energy
Answer:
My answer is radiant energy to chemical energy because it uses the sun which is a form of solar energy and then converts the food to chemical energy for the plant itself
Answer: Radiant energy to chemical energy
Explanation: Right on edge2021
The radius of a small ball is around 3.79747 cm. The radius of a basketball is about 3.16 times larger. What is the ratio of the surface areas of the small ball and a basketball? 2. What is the ratio of their volumes?
Explanation:
The ratio of the areas is the square of the ratio of the radii.
A/A = 3.16² = 9.99
The ratio of the volumes is the cube of the ratio of the radii.
V/V = 3.16³ = 31.6
An object accelerates to a velocity of 230 m/s over a time of 2.5 s. The acceleration it experienced was 42 m/s2. What was its initial velocity?
Answer:
230 = x + 105
x= 125
Explanation:
v = v0 + at
2. Adelia holds a shiny steel spoon with its back (convex surface) facing her eyes at a distance
of approximately 30 cm. She sees an upright image of herself. However, when the spoon
is changed so that the front (concave surface) of the spoon is facing her eyes, an inverted
image is observed.
(a) Explain this situation.
(b) Why is an upright image not seen on the front surface of the spoon at that distance?
Answer:
(a) The convex mirror image, is always upright at all positions, while images formed by concave mirrors are always inverted when the object distance from the mirror is more than the mirrors focal length.
(b) An upright image is not seen for object at a distance from a concave mirror further than the focal length of the mirror, which is the spoon in the question
Therefore, the location of her eyes of approximately, 30 cm, from the mirror is more than the mirror's focal length
Explanation:
