A body of mass 2 kg is accelerated from rest to a velocity of 20 m s^–1 in 5 s. What is the work done and power consumed?

Complete Solution:

Given Data:

• Mass of the body (m) = 2 kg
• Initial velocity (u) = 0 m/s
• Final velocity (v) = 20 m/s
• Time (t) = 5 s

Using the equation of motion: 

v = u + at

Substitute the values: 

20 = 0 + a × 5

a = 20 / 5 = 4 m/s²

Work done is equal to the change in kinetic energy: 

W = ΔKE = (1/2) m (v² - u²)

Substitute the values: 

W = (1/2) × 2 × (20² - 0²)

W = 1 × 400 = 400 J

Power is the work done per unit time: 

P = W / t

Substitute the values: 

P = 400 / 5 = 80 W

Final Answer

• Work Done = 400 J
• Power Consumed = 80 W