Question

A truck starts from rest and Rolls down a hill with a constant acceleration. It travels a distance of 400
m in 20s.Find its acceleration. Find the force acting on it if its mass in 7 tonnes (Hint: 1 tonnes=1000kg).​

Answer 1

Answer:

Explanation:

U =0

S= 400m

T = 20 sec

S= ut + 1/2 at²

400 = 0 + 1/2 (a)(20)²

400 = 1/2 (a)(400)

400 = a × 200

a = 400/ 200

a = 2m/s²

Answer 2

Answer:

Initial velocity, u = 0 (since the truck is initially at rest)

Distance travelled, s = 400 m

Time taken, t = 20 s

According to the second equation of motion:

s=u + 1/2 at square

Where

Acceleration = a

400 = 0 + 1/2 a (20)sq

400 = 1/2 a (400)

a = 2m/s sq

1 metric tonne = 1000kg

Therefore 7 metric tonnes = 7000kg

Mass of truck, m = 7000 kg

From Newton’s second law of motion:

Force, F = Mass × Acceleration

F = ma = 7000 × 2 = 14000 N

Explanation: