Speed and energy

Question 1

A student rolls the SAME skateboard into a cardboard box twice. In Trial 1 the skateboard moves slowly; in Trial 2 it moves faster. In Trial 2 the skateboard slides the box farther. Using this evidence, which explanation is best supported?

Accepted Answer

The faster-moving skateboard has more energy of motion, so it does more to a cardboard box.

Answer

The energy of motion of the skateboard does not depend on how fast it is moving.

Answer

The slower skateboard has more energy of motion because it touches a cardboard box for a longer time.

Answer

The skateboard has the same energy of motion in both trials, so its speed does not matter here.

Question 2

A student rolls the SAME marble into a paper cup twice. In Trial 1 the marble moves slowly; in Trial 2 it moves faster. In Trial 2 the marble pushes the cup farther. Using this evidence, which explanation is best supported?

Accepted Answer

The faster-moving marble has more energy of motion, so it does more to a paper cup.

Answer

The marble has the same energy of motion in both trials, so its speed does not matter here.

Answer

The slower marble has more energy of motion because it touches a paper cup for a longer time.

Answer

The energy of motion of the marble does not depend on how fast it is moving.

Question 3

Sam pushes a wooden block across the floor. The first push is gentle and the block slides a short distance and stops. The second push is hard and the block slides much farther, knocking over a pile of books. Why did the block knock over the books when Sam pushed it harder?

Accepted Answer

Because the block was moving faster, it had more kinetic (energy of motion) and could do more work.

Answer

Because the block became heavier when it moved faster.

Answer

Because the block was larger after the hard push.

Answer

Because the floor was smoother during the second push.

Try three questions

A student rolls the SAME skateboard into a cardboard box twice. In Trial 1 the skateboard moves slowly; in Trial 2 it moves faster. In Trial 2 the skateboard slides the box farther. Using this evidence, which explanation is best supported?

A student rolls the SAME marble into a paper cup twice. In Trial 1 the marble moves slowly; in Trial 2 it moves faster. In Trial 2 the marble pushes the cup farther. Using this evidence, which explanation is best supported?

Sam pushes a wooden block across the floor. The first push is gentle and the block slides a short distance and stops. The second push is hard and the block slides much farther, knocking over a pile of books. Why did the block knock over the books when Sam pushed it harder?

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