Bouncing Ball Experiment

PreLab

Objective: You will use a ball that will bounce to determine how force, mass, acceleration, and energy are all interrelated.

Learning goals:

  1. I can apply Newton's laws in real life situations
  2. I can manipulate formulas to solve for unknown variables
  3. I can create graphs from collected data and communicate results scientifically

Big Idea: By the end of this lab I can answer the following questions:

  1. What is the relationship between mass and the amount of force an object exerts?
  2. How does changing the mass or the height change the amount of energy an object creates when dropped?
  3. How can I show that mechanical energy is conserved?

Data Collection:

1)You will measure the drop height from the bottom of the ball to the floor and record this in the “drop height box”. For the prelab. go to

(Also on my website

To collect your data and record your data in the correct box. For this part of the lab you will only have one rebound height for each drop height and the first, second and third trials should be the same, so for this pre-lab you only need to run one trial of each mass, but you will need to test three objects.

Data

Item # 1: ______Mass of item 1______

Drop Height
(include units) / Rebound Height
(include units) / Time of ball hitting floor in seconds / Force of ball on Floor
(include units) / Energy due to position PE=mgh / Energy due to movement KE= 1/2mv2 / Total energy
ME= KE+PE
Drop height 1: / First bounce:
Second bounce:
Third bounce:
Drop height 2: / First bounce:
Second bounce:
Third bounce:
Drop height 3: / First bounce:
Second bounce:
Third bounce:

Item # 2: ______Mass of item 2______

Drop Height
(include units) / Rebound Height
(include units) / Time of ball hitting floor in seconds / Force of ball on Floor
(include units) / Energy due to position PE=mgh / Energy due to movement KE= 1/2mv2 / Total energy
ME= KE+PE
Drop height 1: / First bounce:
Second bounce:
Third bounce:
Drop height 2: / First bounce:
Second bounce:
Third bounce:
Drop height 3: / First bounce:
Second bounce:
Third bounce:

Item # 3: ______Mass of item 3______

Drop Height
(include units) / Rebound Height
(include units) / Time of ball hitting floor in seconds / Force of ball on Floor
(include units) / Energy due to position PE=mgh / Energy due to movement KE= 1/2mv2 / Total energy
ME= KE+PE
Drop height 1: / First bounce:
Second bounce:
Third bounce:
Drop height 2: / First bounce:
Second bounce:
Third bounce:
Drop height 3: / First bounce:
Second bounce:
Third bounce:

2)Calculate the Force of the ball on the floor and record your answers in the correct boxes. Use F=ma for your calculation

How does force change with increasing height???

How does force change with increasing mass???

3)Use m= mass, g= gravity, and h= drop height to calculate the energy of position (PE) for each of these forces you calculated in step 2.

4) For our purposes we will pretend that this is a closed system and that no energy is being lost to heat. Use the time and the acceleration due to gravity to determine your velocity so that you can calculate the KE or the energy of movement. Notice that at the top of the drop (before you drop the ball) it is not moving, therefore it has no kinetic energy. For our purposes we will assume that kinetic energy is at its max the split second before it hits the floor. Since we cannot tell time that closely let's pretend that the time it hits the floor is the max KE because it has the largest velocity at this point.

So KE= (mass times velocity) divided by two. (Don’t forget about Dear Aunt Sally!!)

What did you notice about the changes in PE and the changes in KE?

5) Total energy of the system (again pretending that this is a closed system) will equal KE+ PE

6) Graph your results

●Use labels, units, and a title for your graph

●Your independent variable is height

●Use the graph to compare height to force in one color

●Use the graph to compare height to energy in another color