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Data Collection: Linear Motion

Linear motion refers to the motion of an object along a straight line.

This experiment will study in activity 1 the linear motion in a horizontal direction and in activity 2 the linear motion in a vertical direction.

Material you need:
· Tennis ball or any small ball [do not use soccer ball or basketball]

· Meter stick or tape measuring

· Timer [you can use your phone]

Activity 1:
· Mark on a smooth horizontal surface (floor) a starting point and then using your mearing tape mark along the floor 2m, 4m and 6 m.

· Start rolling the tennis ball on the horizontal surface (not too fast not to slow) before the starting point. When the ball passes the starting point start the timer and then when the ball passes the 2m point stop the timer. Record the time value in the table under Trial 1.

· Repeat rolling the ball and recording the time the ball takes to travel the 2m distance for two more trials. Record the time values in Table 1 (second column).

· Repeat the starting and stopping of the timer in measuring how long the ball takes to travel 4m.Write the time values in the third column.

· Repeat the starting and stopping of the timer in measuring how long the ball takes to travel 6m.Write the time values in the fourth column.

· Calculate the time average for each distance

· Calculate the average speed:

Average speed = Distance / Time 

(All lengths should be in “s”meter and all times should be in “seconds”)

Data Table 1: Rolling a ball along a horizontal surface

	Time (s): 2-m Distance	Time (s): 4-m Distance	Time (s): 6-m Distance
Trial 1
Trial 2
Trial 3
Average time (s)
Average speed (m/s)

Activity 2:
· Drop the ball from a height d = 2m and use the timer to record the time it takes the ball to reach the floor.

· Repeat this step 7 times and write the time values in the table 2

· Calculate the average time and then calculate t2.

· Calculate the experimental value of acceleration due to gravity “g” by using this equation

Data Table 2: Time trials to drop an object from 2 m

Item	Data
Trial 1 Drop time, t, (s)
Trial 2 Drop time, t, (s)
Trial 3 Drop time, t, (s)
Trial 4 Drop time, t, (s)
Trial 5 Drop time, t, (s)
Trial 6 Drop time, t, (s)
Trial 7 Drop time, t, (s)
Average drop time (s)
t2 (s2) =
Experimental

Calculate the percentage error for acceleration due to gravity” g”. The accepted value is g = 9.8 m/s2.

If your number is very different, please repeat the activity 2.

Questions

:

1. Write Newton’s first Law of Motion (Please see Chapter 2).

2. What is happening with the speed of the ball as the distance traveled on the floor increases (activity 1)? Why do you think is that?

3. What is happening with the speed of the ball as it falls toward the ground (activity 2) Why do you think is that?