Question

Two people push a car for $3s$ with a combined net force of $200N$.
(a) Calculate the impulse provided to the car.
(b) If the car has a mass of $1200kg$, what will be its change in velocity?

• A. (a) $600Ns$ (b) $0.5m/s$
• B. (a) $700Ns$ (b) $0.5m/s$
• C. (a) $800Ns$ (b) $0.5m/s$
• D. (a) $900Ns$ (b) $0.5m/s$

Answer 1

Answer: (A)

(a) $600Ns$ (b) $0.5m/s$

(a) Impulse = impulsive force $\times$ time of impact

$⟹$ $200N\times 3s$

$⟹$ 600N s

(b) Impulse = Change in momentum

= $m\times (v-u)$

$⟹1200kg\times (v-0)=600Ns$

$⟹$ $v=\frac{600}{1200}$

$⟹$ $v=0.5m{s}^{-1}$