6th Mid Unit Contact Forces Lesson 1-5 Assessment

1. Which causes objects to have a change in motion?

• Energy Transfer
• Potential Energy
• Speed
• Size

2. Which scenario below is the same type of collision as two moving cars crashing into each other?

• A golf ball and golf club
• A tree falling onto a house
• Baseball player hitting a fastball
• Stepping on a pair of glasses on the floor

3. Which graph shows the best "line of best fit" for the scatter plot?

• 
• 
• 
• 

4. Kinetic Energy is the energy of ___________.

• Height
• Motion
• Position
• Size

5. There are three types of collisions that tend to happen frequently in soccer: A) Headers, B) Collisions between players heads and C) when players hit the ground. How would the amount of force on the head compare to the amount of force on the object it collides with, in each system A, B, and C?

• In EVERY collision, the peak force on the head would be the SAME as the peak force on the other object in the collision.
• In SOME, BUT NOT ALL collisions, the peak force on the head would be the SAME as the peak force on the other object in a collision.
• In EVERY collision, the peak force on the head would be DIFFERENT than the peak force on the other object in the collision.

Choose 2 true statements that support the previous question:

• Forces always come in pairs, they are acting on each other
• The force is always greater on the object that has more mass
• The force is always greater on the object that has more kinetic energy before the collision
• Peak forces are always equal to each other in size, even if one object has more mass or speed before contact

6. When any two objects make contact, each object applies a force on the other surface they touch. The strength of those forces are...

• the same and in the same direction.
• different but in the same direction.
• the same but in opposite directions.
• different and in opposite directions.

7. How much do you have to push on any object to get it to deform (temporarily or permanently)?

• You need to apply a lot of force before temporary deformation will begin.
• Temporary deformation begins when force is first applied.
• Permanent damage happens when force is first applied.
• There is no deformation when force is applied.

8. The graphs below show the results from a test performed on steel that measured how much the material deformed when pushed with DIFFERENT forces. Based on these graphs what might we conclude about the THICKNESS of these objects?

• The steel object depicted by graph A is THINNER than the steel object depicted by graph B and so it deformed LESS.
• The steel object depicted by graph A is THINNER than the steel object depicted by graph B and so it deformed MORE.
• The steel object depicted by graph A is THICKER than the steel object depicted by graph B and so it deformed LESS.
• The steel object depicted by graph A is THICKER than the steel object depicted by graph B and so it deformed MORE.

9. What happens when an object has reached it's elastic limit (its maximum amount of deformation)?

• Nothing, it stops changing shape.
• It deforms permanently .
• It keeps bending.