Question

Question 6.20 A body of mass 0.5 kg travels in a straight line with velocity where. What is the work done by the net force during its displacement from x = 0 to x = 2 m?

Chapter Work, Energy And Power Page 137

Answer 1

Hi_________

here workdone is equal to change in kinetic energy , because here potential energy is zero

w=50j
hope it help u

Answer 2

body travels in straight line with velocity
v = ax^{3/2}
where a = 5 m-½/s

velocity at x = 0
u { initial velocity } = a(0)^{3/2} = 0

velocity at x = 2m
V { final velocity } = a(2)^{3/2} = 5× (8)½ = 10√2 m/s

we know,
according to Work-energy theorem

workdone = change in kinetic energy
workdone = 1/2 m( Vf² - Vi²)
= 1/2 × 0.5 × { 200 - 0}
=50 Joule

hence, workdone by net Force during 0 ≤ x ≤ 2 is 50 joule