A rocket of mass M is launched vertically fro | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) By the principle of conservation of energy,the total mechanical energy at the surface of the earth must equal the total mechanical energy at the m

Vedclass · Accepted Answer

$\frac{R}{\left( \frac{2gR}{V^2} - 1 \right)}$

Vedclass · Answer

(C) By the principle of conservation of energy,the total mechanical energy at the surface of the earth must equal the total mechanical energy at the maximum height $h$.At the surface: $E_i = K_i + U_i = \frac{1}{2}MV^2 - \frac{GM_eM}{R}$At maximum height $h$: $E_f = K_f + U_f = 0 - \frac{GM_eM}{R+h}$Equating $E_i = E_f$:$\frac{1}{2}MV^2 - \frac{GM_eM}{R} = - \frac{GM_eM}{R+h}$$\frac{1}{2}V^2 = GM_e \left( \frac{1}{R} - \frac{1}{R+h} \right)$Using $g = \frac{GM_e}{R^2}$,we have $GM_e = gR^2$:$\frac{V^2}{2} = gR^2 \left( \frac{R+h-R}{R(R+h)} \right) = \frac{gR^2h}{R(R+h)} = \frac{gRh}{R+h}$$\frac{V^2}{2gR} = \frac{h}{R+h}$$V^2(R+h) = 2gRh$$V^2R + V^2h = 2gRh$$V^2R = h(2gR - V^2)$$h = \frac{V^2R}{2gR - V^2} = \frac{R}{\left( \frac{2gR}{V^2} - 1 \right)}$

$A$ rocket of mass $M$ is launched vertically from the surface of the earth with an initial speed $V$. Assuming the radius of the earth to be $R$ and negligible air resistance,the maximum height attained by the rocket above the surface of the earth is

Similar Questions

Under the influence of a central force,which of the following is conserved?

$A$ body of mass $m$ is lifted up from the surface of the earth to a height three times the radius of the earth. The change in potential energy of the body is (where $g$ is acceleration due to gravity at the surface of the earth).

$A$ missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is

The escape velocity from a planet is $V_e$. $A$ tunnel is dug along the diameter of the planet and a small body is dropped into it. The speed of the body at the centre of the planet will be

Vedclass Test Series

Exam Paper Generator

Online Exam Module