Question

Calculate the kinetic energy of the block if linear momentum of the block is a magnitude of $20\frac{kg.m}{s}$.

• A. 30J
• B. 100J
• C. 10J
• D. 50J
• E. 20J

Answer 1

Answer: (D)

50J

The linear momentum of the block is $p=mv$

The kinetic energy of the block would be given by $K=\frac{1}{2}m{v}^2=\frac{(mv{)}^2}{2m}=\frac{p^2}{2m}$

Thus $K=\frac{{20}^2}{2\times 4}=50J$