Question

A rocket of mass $3\times {10}^{6}kg$ takes off from a launching pad and acquires a vertical velocity of 1 km/s at an altitude of 25 km. The kinetic energy of the rocket is: (Assume g is constant and having a value $10m/s^2$.)

• A. $1.5\times {10}^{12}J$
• B. $1.5\times {10}^{10}J$
• C. $0.5\times {10}^{12}J$
• D. $1.5\times {10}^{16}J$

Answer 1

Answer: (A)

$1.5\times {10}^{12}J$

Given, mass of the rocket, $m=3\times {10}^{6}kg$ ;
velocity of the rocket, $v=1km/s=1000m/s$ ;
Kinetic energy of the rocket, $E_k=\frac{1}{2}m{v}^2$
$=\frac{1}{2}(3\times {10}^6)(1000{)}^2=1.5\times {10}^{12}J$