Question

A student performed an experiment and records the mass and speed of an object traveling at the constant velocity on a frictionless track. Find out which of above trial had the greatest momentum and the trial in which it had the greatest kinetic energy.

Greatest Momentum Greatest Kinetic Energy

• A. Trial 1 Trial 3
• B. Trial 2 Trial 2
• C. Trial 3 Trial 2
• D. Trial 3 Trial 3
• E. Trial 4 Trial 4

Answer 1

The correct option is C Trial 3 Trial 2

Momentum , $p=mv$ and kinetic energy, $K=\frac{1}{2}m{v}^2$

For Trial 1: $p=0.5\times 4=2kg.m/s$ and $K=\frac{1}{2}\times 0.5\times 4^2=4J$

For Trial 2: $p=1\times 3=3kg.m/s$ and $K=\frac{1}{2}\times 1\times 3^2=4.5J$

For Trial 3: $p=2\times 2=4kg.m/s$ and $K=\frac{1}{2}\times 2\times 2^2=4J$

For Trial 4: $p=3\times 1=3kg.m/s$ and $K=\frac{1}{2}\times 3\times 1^2=1.5J$

Thus, Trial 3 has greatest momentum and Trial 2 has greatest kinetic energy.