Understanding Forces

What is an external force?

• A force that is always constant

• A force that acts from within a structure

• A force that acts on a structure from the outside

• A force that only acts on living organisms

In the example of the tree, what prevents it from falling?

• The weight of the tree

• The roots of the tree

• The internal force within the tree

• The external force of the wind

What type of force is the girl applying to the scale?

• Gravitational force

• Magnetic force

• Muscular force

• Frictional force

What happens to a sponge when compression is applied and then released?

• It expands beyond its original size

• It becomes harder

• It remains compressed

• It returns to its original form

Which of the following is an example of compression?

• Bending a metal rod

• Pulling a rope

• Pressing a sponge

• Twisting a rubber band