Purpose: to demonstrate Newton’s 2 nd Law of Motion— the greater the mass of an object, the greater its force if the acceleration remains the same. F=ma (force equals mass times acceleration). Materials: short section of PVC pipe, PVC pipe holder, cup with section cut out of for pipe, a steel ball, a glass marble, a metric measuring tape. Procedure: 1. Set up your apparatus on your lab table as shown in the diagram. Be sure the end of the PVC pipe is positioned just at the mouth of the opening in the cup.
Transcript
Purpose: to demonstrate Newton’s 2nd Law of Motion—the greater the mass of an object, the greater its force if the acceleration remains the same. F=ma (force equals mass times acceleration).
Materials: short section of PVC pipe, PVC pipe holder, cup with section cut out of for pipe, a steel ball, a glass marble, a metric measuring tape.
Procedure:
1. Set up your apparatus on your lab table as shown in the diagram. Be sure the end of the PVC pipe is positioned just at the mouth of the opening in the cup.
2. Place the glass marble at the top end of the PVC pipe and release it without applying any force.
3. The ball will roll down the ramp and cause the cup to move.4. Measure the distance the cup moved—the distance from the
bottom end of the PVC pipe and the front rim of the cup.5. Repeat step 2-4 two more times6. Then repeat steps 2-4 three times using the steel ball.
Data Table
Type of Ball Distance rolled on Trial 1
Distance rolled on Trial 1
Distance rolled on Trial 1
Average Distance Rolled
Glass Marble
Steel Ball
Conclusions:
The ball with the greater mass (steel ball) a. rolled a shorter distance than the ball with less mass (glass
marble).b. Rolled a greater distance than the ball with less mass (glass
marble).
The force here was gravity. Gravity caused the balls to roll down the ramp.
Which ball exerted more force?a. the steel ball (more mass_b. the glass marble (less mass)
Purpose: To investigate how the roughness of a surface affects how far a ball rolls.
Materials: short section of PVC pipe, PVC pipe holder, cup with section cut out of for pipe, a steel ball, a long piece of felt, a long piece of manila paper, a metric measuring tape.
Procedure:
1. Set up your apparatus on your lab table as shown in the diagram. Be sure the end of the PVC pipe is positioned just at the mouth of the opening in the cup.
2. Place the steel ball at the top end of the PVC pipe and release it without applying any force.
3. The ball will roll down the ramp and cause the cup to move.4. Measure the distance the cup moved from the bottom of the PVC
pipe to the front rim of the cup.5. Repeat steps 2 and 4 two more times.6. Place the manila paper under the cup with the end of the paper
touching the bottom end of the PVC pip7. Repeat steps 2-4 three times.8. Place the felt under the cup the same way as you placed the
manila paper in step 6.9. Repeat steps 2-4 three times.
Data Table
Type of Surface
Distance Traveled on Trial 1
Distance Traveled on Trial 2
Distance Traveled on Trial 3
Average Distance Traveled
Lab Table
Manila PaperPiece of Felt
Conclusions:
List the surface based on smoothness. List the smoothest first and the roughest last.
1. _______________________________
2. _______________________________
3. _______________________________
Which surface should have the most friction?________________________
Which surface should have the least friction? ________________________
On which surface did the cup move the farthest distance?
______________________________
On which surface did the cup move the shortest distance?
_____________________________
Discuss your results in terms of how the roughness of a surface affects how much force is necessary to move an object.
