CGPET 2019 Solved Paper

As, we know that,
Escape velocity, v=√2gRe .......(i)
Here, Re= radius of earth and
g= gravitational acceleration.
Given, earth radius shrinks by 0.2%
So,

ΔRe

Re

×100=0.2
From Eq. (i), v2=2gRe ......(ii)
Differentiate, 2vΔv=2gΔRe ........(iii)
Dividing Eq. (iii) by Eq. (ii)
2v

Δv

v2

=

2gΔRe

2gRe

⇒

Δv

v

×100=

1

2

ΔRe

Re

×100 =

1

2

×0.2=0.1
So, escape velocity from the surface of earth is increased by 0.1%.