Question

A particle of mass 0.5 kg travels in a straight line with velocity v = ax3/2 where a = 5 m-1/25-1. What is the
work done by the net force during its displacement from x = 0 to x = 2 m ?
​

Answer 1

50J

Velocity of body is given as v=ax

3/2

where a=5

Initial velocity of body v

i

∣

∣

∣

∣

∣

x=0

=5×0=0 m/s

Final velocity of body v

f

∣

∣

∣

∣

∣

x=2

=5×2

3/2

=10

2

m/s

From work-energy theorem, work done by the force is equal to change in kinetic energy of the body.

∴ W=

2

1

mv

f

2

−

2

1

mv

i

2

Or W=

2

1

(0.5)(10

2

)

2

−

2

1

(0.5)(0)

Or W=

2

1

(0.5)(200)−0

⟹ W=50 J