Question

The work required to increase the velocity of a particle from 18km/h to 72km/h, if mass

of particle is 2kg, is

A) 15J B) 225J C) 275 J D) 375 J​

Answer 1

Answer :

Option D — 375 J

Given :

• Initial velocity (u) = 18 km/h = 5m/s
• Final velocity (v) = 72 km/h = 20m/s
• Mass (m) = 2 kg

To Find :

• Work required to increase the velocity of a particle from 18 km/h to 72 km/h, if mass of particle is 2 kg.

Solution :

Work = 1/2 mv² – 1/2 mu²

= 1/2 × 2 × 20² – 1/2 × 2 × 5²

= 20² – 5²

= 400 – 25

= 375 joules