Question

A particle is projected with velocity kv_e in vertically upward direction from the ground into the space (v_eis escape velocity & k < 1) then the maximum height from the centre of earth to which it can go, will be –

• A. $\frac { \mathrm { R } } { \mathrm { k } ^ { 2 } + 1 }$
• B. $\frac { \mathrm { R } } { \mathrm { k } ^ { 2 } - 1 }$
• C.
• D. $\frac { \mathrm { R } } { \mathrm { k } + 1 }$

Answer 1

Answer: (C)

Answer 2

Total energy of surface

= Total energy at h height

Ž $\frac { 1 } { 2 }$m (kv_e)² + $\left\{ \frac { - \mathrm { GMm } } { \mathrm { R } + \mathrm { h } } \right\}$

Ž h =

From the centre

r = R + h =