On earth, the acceleration of an object in free fall is $9.8 \mathrm{m} {\mathrm{s}}^{-2}$. How fast would an object be travelling after $3 \mathrm{s}$ of free fall if it started from rest?

Set up a ramp that a ball bearing or marble can roll down. The ramp can be made of a half-pipe such as a length of guttering, or with something that has a square profile such as electrical cable trunking. The ramp should be about$1\mathrm{m}$ long. 
Release the ball bearing or marble from the rest at $10 \mathrm{cm}$ from the end of the ramp. Let it roll to the bottom and record the time how long it takes with a stopwatch.

• Repeat this from $20 \mathrm{cm}$ from the end, then in $10 \mathrm{cm}$  increment.

 In this experiment identify one control variable.

Set up a ramp that a ball bearing or marble can roll down. The ramp can be made of a half-pipe such as a length of guttering, or with something that has a square profile such as electrical cable trunking. The ramp should be about$1\mathrm{m}$ long. 
Release the ball bearing or marble from the rest at $10 \mathrm{cm}$ from the end of the ramp. Let it roll to the bottom and time how long it takes with a stopwatch.

• Repeat this from $20 \mathrm{cm}$ from the end, then in $10 \mathrm{cm}$ increment.

Plot a distance-time graph to show the ball's motion (plot time on the x-axis). The average speed of the ball over each distanced can be found using the equation: $\mathrm{v}=\frac{\mathrm{d}}{\mathrm{t}}$ Assuming that the ball is accelerating at a constant rate, the final speed of the ball at the end of the ramp is twice this: $\mathrm{v}=\frac{2\mathrm{d}}{\mathrm{t}}$

Set up a ramp that a ball bearing or marble can roll down. The ramp can be made of a half-pipe such as a length of guttering, or with something that has a square profile such as electrical cable trunking. The ramp should be about$1\mathrm{m}$ long. 
Release the ball bearing or marble from the rest at $10 \mathrm{cm}$ from the end of the ramp. Let it roll to the bottom and record the time how long it takes with a stopwatch.

• Repeat this from $20 \mathrm{cm}$ from the end, then in $10 \mathrm{cm}$ increment.

Plot a distance-time graph to show the ball's motion (plot time on the x-axis). The average speed of the ball over each distanced can be found using the equation: $\mathrm{v}=\frac{\mathrm{d}}{\mathrm{t}}$ Assuming that the ball is accelerating at a constant rate, the final speed of the ball at the end of the ramp is twice this: ${\mathrm{v}}_{\mathrm{final}}=\frac{2\mathrm{d}}{\mathrm{t}}$

Set up a ramp that a ball bearing or marble can roll down. The ramp can be made of a half-pipe such as a length of guttering, or with something that has a square profile such as electrical cable trunking. The ramp should be about$1\mathrm{m}$ long. 
Release the ball bearing or marble from the rest at $10 \mathrm{cm}$ from the end of the ramp. Let it roll to the bottom and time how long it takes with a stopwatch.

• Repeat this from $20 \mathrm{cm}$ from the end, then in $10 \mathrm{cm}$ increment.

Plot a velocity-time graph for the ball's motion (also plot time on the x-axis). 

Set up a ramp that a ball bearing or marble can roll down. The ramp can be made of a half-pipe such as a length of guttering, or with something that has a square profile such as electrical cable trunking. The ramp should be about$1\mathrm{m}$ long. 
Release the ball bearing or marble from the rest at $10 \mathrm{cm}$ from the end of the ramp. Let it roll to the bottom and time how long it takes with a stopwatch.

• Repeat this from $20 \mathrm{cm}$ from the end, then in $10 \mathrm{cm}$ Increment.

Plot a velocity-time graph for the ball's motion (also plot time on the x-axis). 

Use this graph to find the acceleration of the ball.

Here is the displacement -time graph for an object in free fall on the surface of Mars:

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How can you tell that the object was dropped from rest.