A truck starts from rest and rolls down a hill with a constant acceler

1.	A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it, if its mass is 7 metric tonnes.[Hint: 1 metric tonne = 1000 kg]
Answer» The initial velocity of the truck (u) = 0 (As the truck is initially at rest) Distance covered (s) = 400 m, Time (t) = 20 sec Mass of the truck (m) = 7 metric tonnes = 7 x 1000 = 7000 kg To find: Acceleration (a) = ? Force (F) = ? Using second equation of motion S = ut + \(\frac{1}{2}\) at 400 = 0 x 20 + \(\frac{1}{2}\) x a x (20)² ⇒ 400 = \(\frac{1}{2}\) x a x 400 ⇒ a = 2m/s² Now F = ma = 7000 x 2 = 14000 kgm/s² = 14000 Newton

A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it, if its mass is 7 metric tonnes.[Hint: 1 metric tonne = 1000 kg]

Answer»

The initial velocity of the truck (u) = 0 (As the truck is initially at rest)

Distance covered (s) = 400 m,

Time (t) = 20 sec

Mass of the truck (m)

= 7 metric tonnes = 7 x 1000

= 7000 kg

To find: Acceleration (a) = ?

Force (F) = ?

Using second equation of motion

S = ut + \(\frac{1}{2}\) at

400 = 0 x 20 + \(\frac{1}{2}\) x a x (20)²

⇒ 400 = \(\frac{1}{2}\) x a x 400

⇒ a = 2m/s²

Now F = ma = 7000 x 2

= 14000 kgm/s² = 14000 Newton