Understanding Forces and Material Changes

What is friction and what effect does it have on moving objects?

• Friction is a force that speeds up moving objects.

• Friction is a force that slows down or stops moving objects.

• Friction is a force that makes objects float.

• Friction is a force that changes the colour of objects.

Which of the following best describes shear in materials?

• Shear is the force that pulls materials apart.

• Shear is the force that compresses materials.

• Shear is the force that causes layers of material to slide past each other.

• Shear is the force that makes materials expand.

How can you differentiate between plasticity and elasticity in materials?

• Plasticity is when a material returns to its original shape after being stretched, while elasticity is when it stays deformed.

• Plasticity is when a material stays deformed after being stretched, while elasticity is when it returns to its original shape.

• Plasticity and elasticity both mean the same thing.

• Plasticity is when a material changes colour, while elasticity is when it changes size.

Which of the following is an example of a permanent change in a material?

• A rubber band stretching and then returning to its original shape.

• A piece of paper being crumpled and then smoothed out.

• A clay sculpture being moulded into a new shape.

• A balloon being inflated and then deflated.

What is an example of a temporary change in a material?

• A glass bottle breaking.

• A metal rod bending and staying bent.

• A sponge being squeezed and then returning to its original shape.

• A wooden stick snapping in half.

Which of the following best illustrates an internal force?

• The wind pushing against a tree.

• The tension within a stretched rubber band.

• A car pushing against a wall.

• A person lifting a box.

Which of the following is an example of an external force?

• The pressure inside a balloon.

• The gravitational pull on a falling apple.

• The tension in a rope during a tug-of-war.

• The compression within a spring.

What is torsion in the context of forces?

• Torsion is the force that compresses materials.

• Torsion is the force that causes materials to twist.

• Torsion is the force that pulls materials apart.

• Torsion is the force that makes materials expand.

Which of the following scenarios involves compression?

• A sponge being squeezed.

• A rope being pulled from both ends.

• A rubber band being stretched.

• A door being pushed open.

What happens to a material that exhibits elasticity when a force is removed?

• It stays in its deformed shape.

• It returns to its original shape.

• It changes colour.

• It breaks into pieces.