Chapter 3, Problem 30A

Jacob gives his skateboard a push and it rolls across the classroom floor. Emily says that after it leaves Jacob’s hand, his force remains with it, keeping it going. Sophia disagrees and says that Jacob’s push gives the skate-board speed, not force, and that when his hand is no longer in contact the force is no more. Who do you agree with? Discuss this with your classmates.

To determine

The correct statement.

Answer to Problem 30A

Emily is correct.

Explanation of Solution

Introduction:

A skateboard is pushed and rolled against the classroom floor. According to the law of inertia, an object stays at rest or in motion until an external force is applied to it. So, in the given situation, J gives a push to the skateboard. And a push or pull on an object is termed as a force.

J applied a force on the skateboard due to which it sets into motion. So, it will keep moving in motion until an external force is applied to it. This is due to the inertia of motion.

Hence, E is correct that the force applied by J remains with the skateboard, keeping it going.

Conclusion:

E is correct that the force applied by J remains with the skateboard in keeping it going.