I. The objectivesof this lab are to (1) find the initial velocity V_o of a ball thrown vertically (B) determinethe distance the ball travels from the initial level to the top

II. Apparatus: A tennis ball and a stopwatch. For safety, wear a closed-toe shoe.

III. Procedure: Take the ball outside. Set your stopwatch to zero. Throw the ball vertically straight up in the air as hard as you can and catch the ball when it comes back to the same initial level of your hand. Make sure that you start the stopwatch as soon as the ball leaves your hand and stop the stopwatch as soon as you catch the ball. Record the time you read from the stopwatch. The time is the total time the ball spends in air.

IV. Raw Data: Total time ball spends in air = ______________ seconds

V. DATA ANALYSIS: (1)Using your raw data and neglecting air resistance and taking the value of the acceleration due to gravity to be g=9.8 m/s², calculate theinitial velocityV_o with which you threw the ball.(2)Based on your data, and writing your steps, calculate thedistanceD the ball travelled from the initial level of your hand to the top point.

VI. QUESTIONS:

1. As the ball moves up, does its velocity increase, decreaseor stay the same? Explain

2. As the ball moves up, does its acceleration increase, decreaseor stay the same? Explain.

3. If you threw the ball on the Moon (where g = 1.6 m/s²) with the same initial velocity V_oyou obtained from your data analysis, calculate (A) total time ball spends in air on Moon B) the total distance ball travels from the initial level to the top on the Moon.

4. A ball is released from rest on Earth from the top of a building having height H=D=180 m. There is no air resistance. For this question use g = 10 m/s². The whole 180 m distance can be divided into the top half 90 m distance and the bottom half 90 m distance. Writing your steps, calculate the time the ball takes to travel through the bottom half90 m distance.

VII. What are the possible sources of error for this experiment?

VIII. Write down your conclusions. In your conclusions describe if you achieved your objectives and what you have learnt from the experiment.