Eighth Grade Science S8P3.b - Julius Smith | Biblioteka

1

Jillian wants to see how hard she has to kick a soccer ball to score a goal from midfield. Which of the following experiments would help her determine this?

A. kicking the same ball from midfield with different forces, recording amounts of force that allow her to score a goal

B. kicking the same ball from different parts of the field with the same force each time, recording which distance gives her the most goals

C. kicking different balls from the middle of the field with the same force each time, recording how many goals she is able to score

D. kicking different balls from midfield with a different forces, recording which ball allows her to score the most goals

1

Lucia pushed her little sister four feet upward on a swing by exerting a force of 50 Newtons. Lucia wants to determine if her sister will always move four feet upward on a swing when she pushes her with 50 Newtons. Which experiment will work best to determine if Lucia's sister will always travel four feet upward on a swing when pushed with 50 Newtons?

A. an experiment that involves measuring the heights reached by Lucia's sister on the same swing, pushed with the same force, in many repeated trials

B. an experiment that involves measuring the heights reached by Lucia's sister on the same swing, pushed with varying forces, in many repeated trials

C. an experiment that involves measuring the heights reached by Lucia's sister on three different swings, each pushed with the same force, three different times

D. an experiment that involves measuring the heights reached by Lucia's sister on three different swings, each pushed with varying forces, three different times

1

A. The force of her push overcomes the forces of gravity and friction.

B. The force of gravity overcomes the forces of her push and friction.

C. The force of friction overcomes the normal force of the skateboard and the force of gravity.

D. The normal force of the skateboard overcomes the force of her push and the force of gravity.

1

Makayla is conducting an experiment. She places a large block on the ramp and prepares to time the block as it moves down the ramp. When the block is released, it does not move. Makayla places a piece of wax paper between the block and the ramp. This time the block slides easily down the ramp. Which of the following best explains the job of the wax paper?

A. The wax paper reduces the force of gravity acting on the block.

B. The wax paper increases the force of gravity acting on the block

C. The wax paper increases the force of friction acting on the block.

D. The wax paper reduces the force of friction acting on the block.

1

A. Javier forgot to add that forces can never change.

B. Balanced forces only cause objects to change directions.

C. Unbalanced forces only cause objects to stay in the same place.

D. Javier switched the descriptions for unbalanced and balanced forces.

1

A. The force of friction on the wooden block was less than 0.4 N.

B. The force of friction on the wooden block was more than 0.4 N.

C. There were no forces on the wooden block before it was moving.

D. The forces on the wooden block were unbalanced before it was moving.