Question

Weight of body at earth's surface is W. At a depth half way to the centre of earth it will be

• A. W/8
• B. W/4
• C. W/2
• D. W

Answer 1

Answer: (C)

W/2

Answer 2

Using $g_d = g \left( 1 - \frac{d}{R}\right)$ , we get $g_d = g \left( 1 - \frac{R}{2R} \right) = \frac{g}{2}$ $(\therefore d = \frac{R}{2} given )$ Thus weight = $mg_d = \frac{mg}{2} = \frac{W}{2}$