Question

Question 16
An object of mass 100 kg is accelerated uniformly from a velocity of $5m{s}^{-1}to8m{s}^{-1}$ in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

Answer 1

Initial velocity of the object, u = 5 $m{s}^{-1}$
Final velocity of the object, v = 8 $m{s}^{-1}$
Mass of the object, m = 100 kg
Time take by the object to accelerate, t = 6 s
Initial momentum = mu = 100 $\times$ 5 = 500 kg$m{s}^{-1}$
Final momentum = mv = 100 $\times$ 8 = 800 kg$m{s}^{-1}$
Force exerted on the object, F = $\frac{(mv-mu)}{t}$
= $\frac{(800-500)}{6}$
= $\frac{300}{6}$
= 50 N
$\therefore$Initial momentum of the object is 500 kg$m{s}^{-1}$.
Final momentum of the object is 800 kg$m{s}^{-1}$.
Force exerted on the object is 50 N.