Q. A truck starts from rest down a hill with a constant acceleration. It achieves 400 meters in 20 seconds. If the weight of the truck is 7 tons then what will be the force acting on it?

Correct Answer: d) 14000 Newtons

Explanation:
– The truck starts from rest and covers s = 400 m in t = 20 s with constant acceleration a.
– Use s = (1/2) a t^2 ⇒ 400 = (1/2) a (20)^2 ⇒ 400 = 200a ⇒ a = 2 m/s^2.
– Mass of the truck: 7 tons = 7000 kg (taking 1 ton = 1000 kg).
– Net force causing the acceleration: F = m a = 7000 × 2 = 14,000 N.