Mid Unit Contact Forces Lesson 1-5 Assessment

Which causes objects to have a change in motion?

• Transfer of Energy

• Potential Energy
• Speed
• Size

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

Kinetic Energy is the energy of ___________.

• Height
• Motion
• Position
• Size

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

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.

What did we see happen to the different materials as the force applied to them was increased?

• The deformation decreased for all materials at the same rate.
• The deformation increased for all materials at the same rate.
• The deformation increased for all materials but each material had a different rate of deformation.
• There was no deformation.

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.

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.

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.

What are the variables that affect a material's elastic limit? Check all that apply.

• Type of Material
• Color
• Thickness/Shape