A force of 6N acts horizontally on a stationary mass of 2kg for 4s. The kinetic energy gained by the mass is _________
366j
240j
144j
90j
Correct answer is C
F = 6N, m = 2kg, t = 4s, u = 0 (stationary or at rest)
| K.E | = | 1
2 |
mv\(^2\) |
| F | = | mv
t |
from rest
| K.E | = | 1
2 |
m( | Ft
m |
)\(^2\) | = | 1
2 |
× | 2 x (\(\frac{6 \times 4}{2})^2 = 12^2 = 144J\) |