Which describes friction?

The speed of which of the following objects is affected by gravity?

Astronauts design an experiment to test the effect of force on an object. They know that one of the forces we experience on Earth is less on the moon. Which force are the astronauts testing?

A bus driving on the road during the winter drives onto an icy spot and starts to slide. A decrease in which of the following forces causes the bus to slide?

A car traveling down a road approaches a red light. The driver pushes the car’s brakes and the car slows to a stop. What causes the car’s speed to change?

Mrs. Newton’s class designed an experiment to test the effect of force on an object. Four students rolled a tennis ball across floors with different surfaces. Three used smooth surfaces. One student used a rough surface. They measured how far the balls rolled. The table below shows the data they collected.

Analyze the data. Which student rolled a tennis ball across a rough surface?

Lukas designed an experiment to investigate forces and motion. The table shows the distances and times a ball rolled during his investigation. For each trial, the ball started from rest and a force caused it to move.

Analyze the data. During which trial did the greatest force cause the ball to move?

Bodhi designed an experiment to study motion. He used the measured data he collected about the distance a toy car traveled over time to make this graph.

Analyze the pattern shown in the graph. What did Bodhi do to the car between points W and X?

Carla designed an experiment to test velocity. She made the table below to analyze her data.

What important information is missing from Carla’s data table?

Luis is using toy cars to investigate speed. He is changing the length and shape of the track to see the effects on speed. What change could he make to the investigation to make a car go faster?

Keesha designs an experiment to test the effect of force on the motion of a ball. She uses a rubber band wrapped around the legs of a chair to launch the ball. She discovers that the farther she pulls back with the rubber band, the faster the ball travels. Which conclusion should she draw?

Denelle pulled gently on a spring scale. The scale showed a force, but the block did not move. Why not?

Suri tapes batteries to three identical toy cars to give them different masses. Then, Suri measures how far each car rolls when she launches it from the same starting point using the same stretched rubber band. The three toy cars are pictured in the following illustration.

How will the force of the rubber band affect the cars?

A spring scale measures force.

Which is the force that causes the reading on the spring scale shown in the illustration?

Two race cars with the same mass started moving on a race track at the same time. One car reached the finish line of the track in 15 sec, and the other reached the finish line in 20 sec. Why did the cars take different amounts of time to reach the finish line?

Forces can affect an object’s motion. Which of these is a force?

Cars, bicycles, and animals can all be objects in motion. What is it about an object in motion that is constantly changing?

Lin designed an experiment to test the effect of forces on a toy cart that rolls down a long ramp. She covered the ramp with different materials. The table shows the time she measured for each material.

Analyze the data. Which force caused the cart’s time to increase on the carpet?

Maxim wants to design an experiment to test the effect of force on the skateboard. What change could he make to increase the speed of the skateboard?

Velocity and speed are both measurements that describe an object’s motion. What is the difference between velocity and speed?

Which of the following objects will have the greatest change in motion?

Raoul throws a ball into the air and watches it go up for a long time. Then it starts to fall back toward him. What force causes the ball to return to the ground?

Arrows represent the forces applied to an object. A longer arrow means a greater force. Which object will move upward?

When an unbalanced force is applied to an object, the object moves in the direction of the force. Which graph shows how the same force will affect the motion of objects that have different masses?

Two boys are about to use the same force to push a parent and a child. Which describes what will happen?

Tort tests how far three identical toy cars travel under three different conditions.

How is Toji controlling variables for each trial?

Stefan pushes a cart with three books so it just reaches the end of a track. He puts six books onto the cart. What must he use next time so the cart reaches the end of the track?

How can Ryan improve an experiment he designed?

Kaneesha pushes a toy truck and lets it roll across a flat surface. She measures the distance it travels. Then she adds different numbers of wood blocks to her truck.

Which is most likely the measurement missing from the table?

If Alonzo wished to determine how the size of a force affected the motion of an object, which of the following would be the best strategy for his experiment?

A hot air balloon is floating in the air. A person riding in the balloon’s basket throws a heavy bag of sand out of the basket. What effect will this have on the balloon?

Friction can affect an object’s motion. What is friction?

Which surface would probably offer the least friction if you were to slide a box across it?

Karyn designs an experiment to test the effect of force on her bicycle. She rides her bicycle along a path. She finds that when she moves off the path and onto grass, her speed decreases. When she returns to the path, her speed increases. What does she determine caused her change in speed on the grass?

A bobsled glides across the ice and gradually begins to slow down. Which force acts opposite to the bobsled’s motion?