Question

Please answer question 25

Answer 1

▶ Question :

▪ A rocket is going upwards with accelerated motion. A man sitting in it feels his weight increased by 5 times his own weight. If the mass of the rocket including that of the man is 1.0 × 10^4 kg, how much force is being applied by rocket engine ?

▶ Solution :

✒ This question is completely based on the concept of Newton's second law of motion.

Mathematically,

☞ Fnet = m × a

• Fnet denotes net force
• m denotes mass
• a denotes acceleration

☞ As the weight of man increased by 5 times, so acceleration of the rocket is given by

• a = 5g
• a = 5(10)
• a = 50m/s^2

✒ Force applied by rocket engine is

→ F = ma

→ F = 1 × 10^4 × 50

→ F = 5 × 10^5 N

✒ Option B is correct.

Answer 2

Given :

• Mass of rocket including the man = 1×10⁴ kg

• Increase in weight is 5 times the original weight, g = 10 ms¯²

To Find :

• Force applied by the rocket engine

Concept:

• Newton's third law of motion according to which every action has a equal and opposite reaction.

Formula used :

F = ma

▪️F is the applied force

▪️m is the mass

▪️a is the acceleration

Solution :

According to the question, when the weight is increased by 5 times his own weight the acceleration will be

a = 5×10 ms¯²

a = 50 ms¯²

Then,

Force (F) = ma

Force (F) = 1×10⁴ × 50 N

Force (F) = 10⁴ × 50 N

$Force (F) = 5 \times {10}^{5} \: N \:$

Therefore, option (b) is the correct answer.