Understanding Forces and Motion

What is force?

• The speed of an object

• A push or pull upon an object resulting from its interaction with another object

• The resistance of air against a moving object

• The pull of the Earth on objects

What is gravity?

• A type of force that pushes objects away from each other

• The force that attracts a body towards the center of the earth, or towards any other physical body having mass

• The resistance an object encounters when moving over another

• A force that exists only in outer space

How does gravity affect objects on Earth?

• It causes them to float

• It pulls them towards the sky

• It pulls them towards the center of the Earth

• It has no effect

What is air resistance?

• The pull of gravity on an object

• The force that pushes objects closer together

• A type of friction that occurs when an object moves through air

• The force that moves objects in a circular path

What role does air resistance play in skydiving?

• It speeds up the skydiver's fall

• It has no effect on the skydiver

• It slows down the skydiver's fall

• It changes the direction of the skydiver's fall

Which of the following is an example of motion?

• A book lying on a table

• Water flowing in a river

• A painting on a wall

• A tree standing still

What causes motion?

• Only gravity

• Only air resistance

• Forces

• Only friction

How does air resistance affect the motion of a falling object?

• It increases the speed of the object

• It decreases the speed of the object

• It does not affect the speed of the object

• It changes the direction of the object

Which of the following is NOT a form of motion?

• A car braking to a stop

• A balloon floating upwards

• Ice melting in a glass

• A bird flying in the sky

In which scenario is air resistance most likely to be the greatest?

• A pebble falling down a well

• A feather falling to the ground

• A bullet being fired from a gun

• A submarine moving underwater