Question

VIL. Answer the following:-
1. A Car accelerates uniformly from 18kmh in 5s. Calculate
a) The acceleration and b) The distance covered by the car in that time.​

Answer 1

Given :-

• Initial velocity (u) = 0 m/s
• Final velocity (v) = 18 km/h
• Time (t) = 5 sec

To Find :-

1. Acceleration of the car.
2. The distance covered by the car in that time.

Solution :-

First convert km/h into m/s.

⟹ Final velocity = 18 km/h

⟹ Final velocity = 18 × 5/18

⟹ Final velocity (v) = 5 m/s

Case (I), Acceleration of the car.

Applying newton's 1st equation of motion,

★ v = u + at

[ Put the values ]

⟹ 5 = 0 + a × 5

⟹ 5 = 5a

⟹ a = 5/5

⟹ a = 1 m/s² ★

Case (II), The distance covered by the car in that time.

Applying newton's 2nd equation of motion,

★ s = ut + 1/2 × at²

[ Put the values ]

⟹ s = 0 × 5 + 1/2 × 1 × 5²

⟹ s = 0.5 × 1 × 25

⟹ s = 0.5 × 25

⟹ s = 12.5 m ★

Hence,Solved !!