Which of the following statements is true?

Observations are often used to form questions about the world.
The dependent variable is changed by the experimenter.
The best hypotheses are written as answers to a question.
A hypothesis is created at the end of an experiment.

Answers

Answer 1

Answer:

The answer is B.

Explanation:

They are in control of the experiment, they can change it the variables to better help the experiment.

Answer 2

Answer:

b

Explanation: its b


Related Questions

Calculate the density of a rock that has a mass of 32 grams and a volume of

4.5 mL.

Answers

Answer:

85.2ml

Explanation:

1. Which elements would likely have similar properties: two elements in the same group, or two elements in the same period?

2. Fill in the table below with the correct classification of element.

Left side:
Right side:
Zigzag line:

3. Use the periodic table to answer this question: Are the properties of rubidium (Rb) more like those of cesium (Cs) or those of strontium (Sr)? Explain your answer.

4. Use the periodic table at the bottom of the page to identify the elements in the following compounds:
PBS:

KBr:

Rao:

5. Use the periodic table to determine whether each element is a metal or a nonmetal:

Sodium (Na):

Krypton (Kr):

Phosphorus (P):

Answers

Answer:

3. Cs, they are in the same group, mainly sharing characteristics.

Explanation:

The elements in the same group have similar properties. The properties of rubidium is similar to those of strontium because, both are in second group.

What are groups in  periodic table ?

In periodic table, all elements are classified into different periods and groups. The vertical columns in the table is called groups and the horizontal rows are called periods.

The elements in a group have same number of valence electrons and similar chemical and physical properties. For example rubidium and strontium are second group elements and they show similarity in properties.

The elements in the compound, PbS are lead and sulphur and that in KBr are potassium and bromine. Elements in RaO are radium and oxygen. Among the given elements sodium is a metal and krypton and phosphorus are non metals or gases.

Find more on periodic table:

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Write an equation of the line in slope-intercept form.
Please explain.

Answers

Answer:

 y =  [tex]-\frac{1}{4}[/tex]x + 3

Explanation:

The equation of a straight line is given as:

              y  =  mx + c

y and x are the coordinates

m is the slope

c is the y -intercept

 The y-intercept = 3;

Slope  = [tex]\frac{y_{2} - y_{1} }{x_{2} - x_{1} }[/tex]

x₁ = 0

x₂ = 4

y₁ = 3

y₂ = 2

 Slope = [tex]\frac{2-3}{4 -0 }[/tex]  = [tex]-\frac{1}{4}[/tex]

 

       y = mx + c

       y =  [tex]-\frac{1}{4}[/tex]x + 3

A skydiver jumps from a plane and falls for 5 seconds before reaching his terminal velocity. During this 5 seconds interval, describe his acceleration before reaching terminal velocity?

Answers

Answer:

His acceleration during the first five seconds before reaching terminal velocity = (W - D)/m

Explanation:

The terminal velocity is the maximum steady velocity attained by a body falling freely with increasing velocity from rest in a fluid, such as air or water

The net force, F acting on the body falling through the fluid is given as follows;

F = Weight force, W, from gravity - Drag force, D, from the fluid

F = W - D

Given that F = Mass, m × Acceleration, a, we have;

F = m × a

The acceleration, a = F/m = (W - D)/m

His acceleration during the first five seconds before reaching terminal velocity = (W - D)/m.

An unknown substance from planet X has a density of 10 g/mL. It occupies a volume of 80 mL. What is the mass of this unknown substance?

Answers

Answer:

800 mL

Explanation:

D*V=M

You pick out the numbers as well as what it is they represent from the word problem/explanation, then from there plug them in to the equations. Once you do that, you get your product and have the answer.

10*80= 800

What tool of dream analysis says that feelings and urges are hidden inside an event? condensation symbolism projection displacement

Answers

Answer:

Condensation

Explanation:

Answer:

Condensation! Hope this helps!!!

Explanation:

What is thought to make the earth behave as if it contained a huge bar magnet?

Answers

A large amount of molten magnetic material containing Iron is believed to rotate (as a liquid) in the Earth’s core.

We know that the motion of the Moon around the Earth is due
to centripetal force.Then is the motion of the Earth along with moon around Sun due to centripetal force?

Answers

Answer:

YES

Explanation:

Gravity acts as the centripetal force and the velocity earth has keeps it from falling on the sun.

Unit 2 kinetic energy mastery test

Answers

Answer: kinetic energy is Energy of motion.

Explanation:

You are twice as likely to become good friends with the person who is in the dorm room next to you than the person two doors down. This is due to:

A. Proximity.
B. Common Interests.
C. Shared Values.
D. Social Background​

Answers

I think A. Proximity
Since the person is closer, you get to see them more often
The correct answer is A

Pls I need help ASAP

Answers

Answer:

i dont undertsnad what do u ned hep wit?

Explanation:

Two types of energy can be either kinetic or potential energy. Identify those two types. For each type, explain why it can be either kinetic or potential. -Help fast i have my test soon!

Answers

Answer:

All forms of energy are either kinetic or potential. The energy associated with motion is called kinetic energy . The energy associated with position is called potential energy . Potential energy is not "stored energy".

Explanation:

All forms are mostly kinetic!!

Two identical cars are driving along the motorway. Car A is travelling at 50 km/h and Car B is travelling at 80km/h. Which car has the most drag acting on it?

Answers

Answer:

i think it is car B because  the greater the speed, the greater the drag force acting on the vehicle

Explanation:

A motorist, traveling east on an open highway, sets his cruise control at 90.0 km/h. How far will he travel in 0.75 hours?

Answers

Answer:

The answer is 67.5 km

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

distance = velocity × time

From the question we have

distance = 90 × 0.75

We have the final answer as

67.5 km

Hope this helps you

Answer: 67.5 km

Explanation:

Distance is the velocity and time.

90 x 0.75 = total distance

The distance is represented as 67.5 km/h.

Hope this helps!

The output of a solar panel powers a small pump. The pump operates a garden water fountain. The output of the solar panel is 10 V and the current supplied to the pump is 0.25 A. Calculate the electrical power generated by the solar panel.

Answers

That’s tuff ima get in give me a min

The power generated by solar panel will be "2.7 W".

According to the question,

The values are:

Output of solar panel,

10 V

Current,

0.25 A

The electrical power generated will be:

→ [tex]P = VI[/tex]

By substituting the given values is the above formula, we get

→     [tex]= 10\times 0.27[/tex]

→     [tex]=2.7 \ W[/tex]

Thus the above answer is right.

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PLZ EXPLAIN THE EQUATION AND I WILL GIVE BRAINLIST You are out and about in the country and your father sees a rock that he really wants in the yard. Now you must get the very heavy rock into the back of a truck. The truck bed is 3 feet off the ground. Your father pulls out a 5-foot plank and begins to set up a ramp. At the same time, you (who know about mechanical advantage!) have found a plank that is 8 feet long, and you show it to your father. Which plank will give you the most mechanical advantage? Calculate the MA for each plank

Answers

Answer:

The 8 foot long plank

Explanation: hope this helps :)

Which of the following is true regarding mixtures? a. One substance not combined with any other substances. b. Two or more substances physically mixed and can be separated. c. Two or more substances that are impossible to separate d. One substance that forms a compound alone.

Answers

Answer:

aerga

dggzsd

Explanation:

szsdrgzsedg


An object with a mass of 15 kg accelerates 10.0 m/s2 when an unknown force is applied to it. What is the
amount of the force

Answers

Answer:

f=mass × acceleration

=15×10

=150

You try to hit an annoying pigeon by throwing a ball straight up into the air with a velocity of 16 m/s. What is its velocity 0.5s into flight?

Answers

Answer:

20.9 m/s

Explanation:

Given that,

Initial velocity, u = 16 m/s

We need to find its velocity 0.5 s into flight when a ball straight up into the air. Let it is v. It will move under the action of gravity. Using first equation of motion to find it as follows :

v=u+at

Here, a = g

v = 16 + 9.8(0.5)

v = 20.9 m/s

So, the final velocity is 20.9 m/s.

Annie has 100 mL of honey. The honey has a mass of 145 g. What is the density of the honey?

Answers

Answer:

The answer is 1.45 g/mL

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question we have

[tex]density = \frac{145}{100} \\ [/tex]

We have the final answer as

1.45 g/mL

Hope this helps you

On the moon, the gravity is 1/6 that of Earth. While on the moon, Buzz Aldrin carried on his back a support system that would weigh over 1760 N on Earth. a) What did the backpack weigh on the moon? b) What was its mass on the moon? please show the work

Answers

Answer:

a) 293.[tex]\bar 3[/tex] N

b) Approximately  179.41 kg

Explanation:

The given parameters are;

The gravity (gravitational acceleration) on the moon = 1/6 × The gravity on Earth

The weight of the support system Buzz Aldrin carries = 1760 N

a) Given that the weight  of the support system on Earth = Mass of the support system, m × Gravity, g (Acceleration due to gravity) = m·g

The weight  of the support system on Earth = m·g

We have;

The gravity on the moon = 1/6 × g

∴ The weight of the support system on the moon = Mass of the support system, m ×  1/6 × g = m·g/6

∴ The weight on the of the support system on the moon = m·g/6 = 1/6 × m·g = 1/6 × m·g = 1/6 × The weight  of the support system on Earth

The weight on the of the support system on the moon = 1/6 × 1760 N = 880/3 N = 293.[tex]\bar 3[/tex] N

b) The mass, m, of the support system on the moon = The mass, m, of the support system on Earth

The mass, m, of the support system on Earth = Weight of the support system/(Gravity(acceleration due to gravity))

∴ The mass, m, of the support system on Earth = 1760/9.81 ≈ 179.41 kg

∴ The mass, m, of the support system on the moon ≈ 179.41 kg.

A 5.0kg concrete block accelerates down a 34 degree slope at 4.2 m/s^2. Find the Coefficient of friction between the block and the slope.

Answers

Answer:

The coefficient of friction between the block and the slope is 0.16.

Explanation:

We can find the coefficient of friction between the block and the slope by using Newton's second law:        

[tex] \Sigma F = ma [/tex]

[tex]P_{x} -\mu N = ma[/tex]

[tex] mgsin(\theta) - \mu mgcos(\theta) = ma [/tex]    (1)              

Where:

m: is the mass of the block = 5.0 kg

a: is the acceleration = 4.2 m/s²

θ: is the angle = 34°

μ: is the coefficient of friction =?

g: is the gravity = 9.81 m/s²

By entering the above values into equation (1) we have:

[tex] gsin(\theta) - \mu gcos(\theta) = a [/tex]                  

[tex] \mu = \frac{gsin(\theta) - a}{gcos(\theta)} = \frac{9.81 m/s^{2}*sin(34) - 4.2 m/s^{2}}{9.81 m/s^{2}*cos(34)} = 0.16 [/tex]

Therefore, the coefficient of friction between the block and the slope is 0.16.

I hope it helps you!        

Please help me and I will mark you the brainiest

Answers

Answer:

Right direction (i.e towards B).

Explanation:

From the question given above, we can see that the car is accelerating in the left direction (i.e towards D).

Friction is the force that tends to oppose the motion of an object. Since the car is moving in the left direction (i.e towards D) then, the frictional force acting on the wheel will be in the opposite direction i.e right direction (i.e towards B).

Write an equation of the line in slope-intercept form.

Answers

the answer would be y=1/3x+2

why speed is a derived quantity?​

Answers

Answer:

Explanation:

The speed is a derived quantity as it being derived from a defined set of quantities through a formula. There are only 7 fundamental quantities which are being defined with their individual fundamental units. Of those, length and time are two of them.Thus, it is a derived quantity

Explain a principal of moments of a force

Answers

The principle of moments states that when a body is balanced the total clockwise moment about a point equals the total anticlockwise moment about the same point.Equation.Moment=Force F×perpendicular distance from the pivot do.

A player kicks a football from ground level with a velocity of
magnitude 27.0 m/s at an angle of 30° above the horizontal.
What is the horizontal distance the ball travels?
(hint: d= 1/2 at^2)

Answers

Answer:

37.33m

Explanation:

To calculate the distance using d= 1/2 at², the time taken for this projectile object (ball) must be calculated.

Time of a projectile = 2u sinθ/ g

Where u = velocity = 27m/s

g = 9.8m/s²

θ = 30°

T = 2usinθ/ g

T = 2 × 27 × sin 30°/9.8

T = 54sin30°/9.8

T = 27/9.8

T = 2.755

T = 2.76s

If the time taken for the ball to move is 2.76s, the distance travelled is:

D = 1/2at²

D = 1/2 × 9.8 × 2.76²

D = 1/2 × 9.8 × 7.6176

D = 74.65248/2

D = 37.33m

The horizontal distance the ball travels is 37.33m

The horizontal distance travel by ball is 37.32 meters.

First we have to calculate time of projectile,

               [tex]Time=\frac{2usin\theta}{g}[/tex]

Where g is acceleration due to gravity and u is velocity.

Given that, [tex]u=27m/s, \theta=30[/tex]

Substitute values in above relation.

       [tex]Time=\frac{2*27*sin30}{9.8}=\frac{2*27*0.5}{9.8}=2.76s[/tex]

The horizontal distance is given by,

              [tex]d=\frac{1}{2}gt^{2}\\ \\ d=\frac{1}{2}*9.8*(2.76)^{2} \\\\d=37.32m[/tex]    

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The mass of the sun is 1.9891030 kg and the mass of the Earth is 5.9721024kg. If the Earth’s acceleration toward the sun is 0.0059 m/s/s, what is the sun’s acceleration toward the Earth?

Answers

Answer:

this is the answer according to my calculations

Explanation:

0.001.9

can someone help rn please!! thank you sm!!

Answers

I think it’s weight
Mass is the measure of its resistance to acceleration when net force is applied
Pounds and Kilograms definitely cannot be the answer
So the only logical answer is weight
Hope this helps

If the starting population of 5 rabbits grows at 200% each year, how many will there be 50 years?

Answers

Answer:

Alot of god dam rabbits

Explanation:

Answer:

million rabbits becauseeverything

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