AP EAPCET 23-Aug-2021 Shift 2 Paper

Given, radius of Earth and Mars are 6400‌km and 3200‌km , respectively.
Mass of Earth =10 (Mass of Mars)
Me=10Mm
We know that, acceleration due to gravity at surface of a planet is
g=

GM

R2

,
where, M= mass of planet and R= radius of planet.
Taking the ratio of acceleration due to gravity of Mars to Earth,

gm

ge

=

GMm∕Rm2

GMe∕Re2

=

Mm

Me

×(

Re

Rm

)2
By substituting the values, we get

gm

ge

=

1

10

×(

6400

3200

)2=

1

10

×4
⇒gm=

2

5

ge
Given, the weight on earth's surface,
we=mge=200N
∴ Weight on the Mars surface,
wm=mgm=

2

5

(mge) =

2

5

×200N=80N