Question

A force produces an acceleration of $5.0m/s^2$ when it acts on a body of mass 2 kg for 2 seconds. Find the work done by the force.

• A. 50 J
• B. 80 J
• C. 100 J
• D. 120 J

Answer 1

Answer: (C)

100 J

Given mass of body m = 2 kg

acceleration, $a=5m{s}^2$

Initial velocity, v = 0 m/s (at rest initially)
time t = 2 sec

let the displacement in 2 sec be s

s = ut + $\frac{1}{2}a{t}^2$ = 0 $\times 2+\frac{1}{2}\times 5\times 2^2$ = 10 m

work done, w = force $\times$ displacement w = m $\times$a $\times$s = 2 kg $\times 5m{s}^2\times$ 10 m = 100 J

Hence work done by the Force will be 100 J