Question

While launching a satellite of mass 10^4 kg, a force of 5 * 10^5 N is applied for 20s. The velocity attained by the satellite at the end of 20s, is
(a) 4 km/s (b) 3 km/s
(c) 1 km/s (d) 2 km/s

Answer 1

Given:

While launching a satellite of mass 10^4 kg, a force of 5 * 10^5 N is applied for 20s.

To find:

Velocity of rocket at end of 20 sec ?

Calculation:

• First , let's find out the acceleration of rocket.

$a = \dfrac{f}{m}$

$\implies \: a = \dfrac{5 \times {10}^{5} }{ {10}^{4} }$

$\implies \: a = 50 \: m {s}^{ - 1}$

Now, applying Equation of Kinematics:

$v = u + at$

$\implies \: v = 0 + (50 \times 20)$

$\implies \: v =1000 \: m {s}^{ - 1}$

$\implies \: v =1 \: km \: {s}^{ - 1}$

So, velocity attained is 1 km/sec.