Question

A 200 gm mass has velocity of $(3\hat{i}+4\hat{j})$m/s at certain instant. Find its kinetic energy.

• A. $2.5J$
• B. $0.5J$
• C. $0.8J$
• D. $1.5J$

Answer 1

The correct option is A $2.5J$

First we will calculate the Magnitude of velocity so $v=\sqrt{3^2+4^2}=5m/s$

Now m=200 gm or 0.2 kg

So $KE=\frac{m{v}^2}{2}=\frac{0.2\times 5^2}{2}$

so $KE=2.5J$