Question

A father and his young daughter are ice skating. They face each other at rest and push each other, moving in opposite directions. Which one has the greater final speed? Explain.

Short answer

The obtained result is that the daughter’s final speed is greater.

Step-by-step solution

Step 1. Newton’s third law

Newton’s third law states that when two specific components interact, the forces utilized by them on each other will be identical in magnitude but opposite in direction.

A father and daughter are ice skating. At rest, they push each other and move in the opposite directions. The magnitude of force will be equivalent for both of them by considering the third law of Newton.

Step 2. Determine who has the greatest final speed

The relation of acceleration can be written as:

$\begin{array}{c}F=ma\\ a=\frac{F}{m}\end{array}$

Here, F is the force, m is the mass, and a is the acceleration.

Since the daughter is younger, so her mass is less than the mass of her father. From the above relation, it can be said that the daughter’s acceleration is more.

The forces or accelerations are exerted at the same time interval, that is, when they are in contact. Therefore, the final speed of the daughter will be more compared to her father.

Thus, the daughter’s final speed is greater.