Help with Constant Acceleration Lab

daodude1987

[SOLVED] Help with Constant Acceleration Lab

Hey guys, thanks for reading my post. I'm really confused about a lab that was assigned by my teacher. I will try to explain the whole lab the best I can.

Lab: The Balls Lab

Purpose of the Lab: To determine the initial velocity (Vo) and maximum height (dy) of a thrown (and hit) ball

Procedure/Materials:
Materials: tennis ball, tennis racket, stop watch
1. Throw a ball straight up into the air
2. Measure the time the ball is in the air and comes down
3. Due three trials

Data: (here are the 3 time results I got for the ball)
Throwing
Trial 1- 3.21 seconds
Trial 2- 3.10 seconds
Trial 3- 2.94 seconds
Average- 3.08 seconds

Hitting the ball with tennis racket
Trial 1- 1.41 seconds
Trial 2- 2.88 seconds
Trial 3- 1.87 seconds
Average- 2.05 seconds

Conclusion:
Ok here is the problem... I have no clue how to start solving for the initial velocity (Vo) for the average of the ball thrown and hit in the air. At first I thought the initial velocity of the thrown ball was 0 because that is usually the velocity of any object at rest and then going into the air. But my teacher said it wasn't because he wanted the intial velocity from when it left my hand not when it is at rest, which is 0. He also told me that I needed to use one of the equations of motion for constant acceleration such as: Vf=Vo+at, d=1\2(Vf+Vo)t, d=Vo=1/2at(squared), or 2ad=(Vf)squared-(Vo)squared and the acceleration of gravity, -10 m/s to solve for Vo. But he wasn't clear on which one. Also it seems to me that each of these equation require the value of Vo itself! I am also very confused at how to find the height of the thrown ball (dy) because y is not given as a variable in any of these equations.

If you guys can show me how I can solve for the initial velocity (Vo) and the maximum height(dy) of the of the ball thrown using any of the equations above or even your own methods, please enlighten me with you explanation. I am most grateful.

Thank you for taking the time to answer.

Last edited by a moderator:
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wolfgang

Hi,

Initial velocity:
You must think what is the relation between the time that the ball goes up and the total time of the movement you have measured. Then you must think what happens to the velocity of the ball when it reaches the highest spot of its orbit. With the above data and the proper equation of motion you can calculate the initial velocity.

Height of the throw:
You have calculated the initial velocity so the only thing you need is the time that the ball needed to get from your hand to its highest spot.

Sorry, I don’t give you the exact equations and values of time and velocity but if you fallow the steps I have written above I am sure that you will solve the problem by your own. You must think if you want to gain knowledge and on the other hand you will feel so great when you find the solution.

Excuse me for the sermon.

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The text is a student's request for help with a physics lab, specifically about calculating the initial velocity and maximum height of a ball thrown and hit with a tennis racket. The student provides lab data and describes their confusion about which equations to use.
single_question_with_answer

the text contains a single mathematical question (how to calculate the initial velocity and maximum height of the ball) and an answer is provided in the form of guidance on how to approach the problem.
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
Help with Constant Acceleration Lab

daodude1987

[SOLVED] Help with Constant Acceleration Lab

Hey guys, thanks for reading my post. I'm really confused about a lab that was assigned by my teacher. I will try to explain the whole lab the best I can.

Lab: The Balls Lab

Purpose of the Lab: To determine the initial velocity (Vo) and maximum height (dy) of a thrown (and hit) ball

Procedure/Materials:
Materials: tennis ball, tennis racket, stop watch
1. Throw a ball straight up into the air
2. Measure the time the ball is in the air and comes down
3. Due three trials

Data: (here are the 3 time results I got for the ball)
Throwing
Trial 1- 3.21 seconds
Trial 2- 3.10 seconds
Trial 3- 2.94 seconds
Average- 3.08 seconds

Hitting the ball with tennis racket
Trial 1- 1.41 seconds
Trial 2- 2.88 seconds
Trial 3- 1.87 seconds
Average- 2.05 seconds

Conclusion:
Ok here is the problem... I have no clue how to start solving for the initial velocity (Vo) for the average of the ball thrown and hit in the air. At first I thought the initial velocity of the thrown ball was 0 because that is usually the velocity of any object at rest and then going into the air. But my teacher said it wasn't because he wanted the intial velocity from when it left my hand not when it is at rest, which is 0. He also told me that I needed to use one of the equations of motion for constant acceleration such as: Vf=Vo+at, d=1\2(Vf+Vo)t, d=Vo=1/2at(squared), or 2ad=(Vf)squared-(Vo)squared and the acceleration of gravity, -10 m/s to solve for Vo. But he wasn't clear on which one. Also it seems to me that each of these equation require the value of Vo itself! I am also very confused at how to find the height of the thrown ball (dy) because y is not given as a variable in any of these equations.

If you guys can show me how I can solve for the initial velocity (Vo) and the maximum height(dy) of the of the ball thrown using any of the equations above or even your own methods, please enlighten me with you explanation. I am most grateful.

Thank you for taking the time to answer.

Last edited by a moderator:
Related Other Physics Topics News on Phys.org

wolfgang

Hi,

Initial velocity:
You must think what is the relation between the time that the ball goes up and the total time of the movement you have measured. Then you must think what happens to the velocity of the ball when it reaches the highest spot of its orbit. With the above data and the proper equation of motion you can calculate the initial velocity.

Height of the throw:
You have calculated the initial velocity so the only thing you need is the time that the ball needed to get from your hand to its highest spot.

Sorry, I don’t give you the exact equations and values of time and velocity but if you fallow the steps I have written above I am sure that you will solve the problem by your own. You must think if you want to gain knowledge and on the other hand you will feel so great when you find the solution.

Excuse me for the sermon.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
user
The text is a student's request for help with a physics lab, specifically about calculating the initial velocity and maximum height of a ball thrown and hit with a tennis racket. The student provides lab data and describes their confusion about which equations to use.

TYPE: SINGLE_QUESTION_WITH_ANSWER

The text contains a single mathematical question (how to calculate the initial velocity and maximum height of the ball) and an answer is provided in the form of guidance on how to approach the problem.