Force and Motion

When is friction needed during the course of motion?

• to speed up motion

• to slow down motion

• to keep motion at the same speed

• to keep motion in the same direction

A force causes an object to be in motion. Which will most likely happen to the motion of the object if a weaker force begins acting on the object in the opposite direction?

• The speed of the object will increase.

• The speed of the object will decrease

• The speed of the object will remain the same.

• The object will immediately stop moving.

A student uses the same force to push a golf ball, a ping pong ball, a bowling ball, and a baseball. Which will move the fastest?

• The golf ball

• The ping pong ball

• The bowling ball

• The baseball

The graphs show two delivery trucks traveling on the same highway.

Which best describes the speed of the two trucks?

• Truck A is slowing down, and Truck B is speeding up.

• Truck A is speeding up, and Truck B is not changing speed.

• Truck A is not changing speed, and Truck B is slowing down.

Martin needs to push a box up a ramp.

Which forces will Martin work against MOST when he pushes the box up the ramp?

• inertia and magnetism

• magnetism and friction

• inertia and magnetism

• friction and gravity

Which is a force that keeps the planets in orbit around the Sun?

• inertia

• gravity

• magnetism

• solar energy

A plane carrying bags has a mass of 50,000 kg. After delivering the bags, it has a mass of 30,000 kg. Which would best describe how the plane’s motion would be affected on the way back?

• The plane would travel at a faster speed.

• The plane would travel at a slower speed.

• The plane would travel at the same speed.

A group of students hiked at a rate of 4 kilometers per hour through the park. The journey took 4 hours. How far did the group travel? (distance = speed × time)

• 13 km

• 14 km

• 15 km

• 16 km

A car is traveling 50 miles per hour. It leaves Boston, Massachusetts at 5 a.m. and is traveling to Hartford, Connecticut, which is 100 miles away. Without traffic problems or stops, about what time should the car arrive in Hartford?

• 6:00 a.m

• 6:50 a.m.

• 7:00 a.m.

• 7:50 a.m.

Jason plays a game with a tower of blocks. Jason removes as many blocks as he can from the middle of the tower while it remains standing. the picture shows the tower at two different times during the game.

Which BEST explains why the tower remains standing with blocks missing?

• friction

• gravity

• magnetism

• balanced forces