Page 56 - Force 10

Numerical:
3
Q.2.) Mass and radius of the moon are 7.2 × 10 22 kg and 1.7 × 10 km resp.
calculate the acceleration due to gravity of the moon and weight of a
man 70 kg on the moon.

Ans: let the mass of moon ( M) = 7.2 × 10 22 kg ,

3
Radius of the moon (R) = 1.7 × 10 km
= 1.7 × 10 m ,
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mass of a man on moon (m) = 70 kg

acc. due to gravity (g) = ?

As we know, g =

2 −11 22

= 6.67×10 × 7.2×10

1.7 ×10 6 2
= 1.6 m/s 2

Now, weight of a man (W) = m × g

= 70 × 1.6

= 116.2 N

Hence, the acc. due to gravity is 1.6 m/s and weight is 116.2 N on the
2

surface of moon.