Question

The mass of body on surface of the earth is 100 kg. What will be its (i) mass and (ii) weight at an altitude of 1000 km ? ( R = 6400 km, g = 9.8 m / s²) (Ans : 100 kg, 733 N)

Answer 1

(i) Mass doesn't change. It remains constant in all situations. so, mass of body at an altitude of 1000km must be 100kg.

(ii) we know, $g=\frac{g_0}{\left(1+\frac{h}{R}\right)^2}$

$g_0=9.8m/s^2$

h = 1000km and R = 6400 km

now, g' = 9.8/(1 + 1000/6400)² = 7.33 m/s²

so, weight = mass × acceleration due to gravity

= 100kg × 7.33 m/s² = 733N.

Answer 2

Answer:

1) m = 100 kg , 2) wt = 733 N

Explanation:

1) Mass does not change. It remains constant.

  ∴ m = 100 kg

2) We know that,

    gh = g/(1+h/R)²

          = 9.8/(1+1000/6400)²

          = 9.8/1.337

     gh = 7.33 m/s²

   Now,

            Weight = mass × acceleration due to gravity

            wt. = 100 × 7.33

            wt. = 733 N

HOPE THIS HELPS YOU!!!