Force & Motion

Which of the following conclusions can Felipe and Marsha make about the forces that cause the blocks to move down the tray?

• the force of friction is the same on each block

• the force of friction causes the speed of each block to increase

• the force of gravity causes all the blocks to move at the same speed

• the force of gravity is greater than the force of friction on all the blocks

Frank uses a bowling ball to demonstrate how energy can cause changes. Which of the following actions would NOT demonstrate a change caused by Frank applying energy to the ball?

• He holds the bowling ball in both hands

• He spins the bowling ball with one hand

• He rolls the bowling ball across the floor

• He lifts the bowling ball to place it on a shelf

Placing which of the following objects at point X will cause the bar magnet to move away from point X?

• an iron nail

• an aluminum can

• the north end of another bar magnet

• the south end of another bar magnet

How does removing the books affect the motion of the bookcase?

• the mass is decreased, making the bookcase move faster

• the gravity is increased, making the bookcase move slower

• the friction is increased, making the bookcase move slower

• the mechanical energy is decreased, making the bookcase move faster

What force is causing the motion?

• the pull of the child on the wagon

• the push of the child on the wagon

• the pull of the wagon on the child

• the push of the wagon on the child

How has a force affected motion?

• The force of the bat caused the batter to stop swinging.

• The force of the ball caused the batter to stop swinging.

• The force of the bat caused the ball to change direction.

• The force of the ball caused the bat to change direction.

What question can Jude answer with this investigation?

• How many trials are needed to investigate how fast materials slide?

• How is friction different with different materials?

• Is a table the best way to record data from an investigation?

• What force is need to push a block down a ramp?

Miranda is investigating the concept of gravity. She dropped a flat sheet of paper and a sheet of paper crumpled into a ball from the same height. She repeated the procedure from various heights.

For every trial, the paper ball hit the floor in less time than the flat sheet of paper. Why did the paper ball always fall faster?

• Gravity is stronger for the paper ball.

• Air can get trapped in the paper ball.

• There is no friction for a ball-shaped object.

• The flat sheet was affected more by friction (air resistance)

What does the picture show about magnetism?

• Magnetism is a contact force, and magnets can either attract or repel each other.

• Magnetism is a non-contact force, and magnets can either attract or repel each other.

• Magnetism is a contact force, and magnets can be pushed together and pulled apart.

• Magnetism is a non-contact force, and magnets can be pushed together and pulled apart.

Why do the bird's wings move down when it flies?

• The wings need to go down some of the time to reduce friction.

• The wings need to point in the direction of the force of gravity.

• The wings move from up to down to avoid the friction between the air and the wings.

• The wings push down on the air to overcome gravity.