Pre-Lab Questions

1. In one of your experiments, you will roll a marble down a ramp to provide an initial horizontal velocity. Suppose you start the marble at rest (vo = 0 m/s) and it travels a distance of,d, down the ramp. Use 1-D kinematics to predict the velocity of the ball (vf) at the bottom of the ramp.Hint: the acceleration of the ball down the ramp is 9.81*sin() m/s2 where is the angle of the ramp. Record you answer in variables (you will calculate the velocity with magnitudes when you perform the experiment).
2. Use the kinematic equations to derive a general equation for the time it takes a ball dropped from rest at vertical height,h, to reach the ground.
3. Use the result from Question 2 to write a general equation for the distance travelled by a projectile that is rolling off a table of height,h, with a horizontal speed,v0x.

Experiment 1: Distance Traveled by a Projectile

Data Sheet

Table 1. Range and Velocity of Projectile at Ramp Distance 1

Ramp Incline (degrees)	48
Ramp Distance (m):	36.5 cm
Trial	Measured Distance (m)
1	35.6 cm
2	38 cm
3	39 cm
4	38cm
Average	37.65cm

Table 2. Range and Velocity of Projectile at Ramp Distance 2

Ramp Distance (m):	25.5
Trial	Measured Distance (m)
1	28 cm
2	28 cm
3	29cm
4	29 cm
Average	28.5cm

Table 3. Range and Velocity of Projectile at Ramp Distance 3

Ramp Distance (m):	12.5
Trial	Measured Distance (m)
1	3.5 cm
2	2 cm
3	.5cm
4	1cm
Average	1.75cm

Post-Lab Questions

1. Use your predictions of velocity and range from the Pre-Lab Questions and the data recorded from your experiment to complete Table 4.

Table 4. Velocity and Range Data for all Ramp Distances.

Ramp Distance (m)	Calculated velocity (m/s)	Predicted Range (m)	Average Actual Range (m)	Percent Error

1. How do your predictions compare to the observed data? Explain at least two reasons for the differences.
2. If you were to fire a paintball pellet horizontally and at the same time drop the same type of paintball pellet you fired from the paintball gun, which pellet would hit the ground first and why is this so?
3. Suppose you altered your existing ramp so that the marbles had twice their initial velocity right before leaving the ramp. How would this change the total distance traveled and the time that the marbles were in the air?
4. Describe the acceleration of the marble after it leaves the ramp. Use kinematic equations to support your discussion.