OnlineCBT
Physics · GRAVITATION
हिन्दीThe work done in lifting a particle of mass \( m \) from a distance \( r_1 \) to \( r_2 \) (where \( r_2 > r_1 > R_E \)) from the centre of the Earth of mass \( M_E \) is:
Correct answer · Option 1
\( -G M_E m (\frac{1}{r_2} - \frac{1}{r_1}) \)
Explanation
Work done by the gravitational force is W_12 = integral from r_1 to r_2 of (-G M_E m / r^2) dr = -G M_E m (1/r_2 - 1/r_1) = G M_E m (1/r_1 - 1/r_2). In NCERT Eq. 7.24, W_12 is defined as -G M_E m (1/r_2 - 1/r_1).
