Question

A 20kg box is at rest on a friction less surface.then,a man pushed the box to a velocity of 3 m/s for 2 s

Answer 1

The given surface is friction less and initial velocity of the block is 0(rest).

Acceleration is change in velocity per unit time.

$$acceleration(a)= \frac{\triangle V}{\triangle t} \newline a=\frac{3}{2}\newline acceleration = 1.5 \ m/s^2$$

Thus the force applied on the box by the man = m*a

where m- mass of box and a- acceleration.

$$Force(F)=Mass(m)\times Acceleration(a) \newline F=20 \times1.5 \newline F=30 \ N$$