Question

A rocket of mass $100 \,kg$ burns $0.1\, kg$ of fuel per sec. If velocity of exhaust gas is $1 \,km/s^{-1}$, then it lifts with an acceleration of

• A. $ 1000\,ms^{-2}$
• B. $ 100\,ms^{-2}$
• C. $ 10\,ms^{-2}$
• D. $1\, ms^{-2}$

Answer 1

The Correct Option is D

Given that, \(\frac{v}{d t}=0.1\, kg / s\); 
mass of the rocket \(=100\, kg\) and \(v=1\, km / s =1000\, m / s\)
Thrust on the rocket, \(F=v \frac{d m}{d t}\)
Now, \(=1000 \times 0.1\)
\(F=M a\)
\(\therefore a =\frac{1000 \times 0.1}{100}\)
\(=1\, m / s ^{2}\)

When an item moves in a specific direction, force is connected to the motion of translation. Energy, however, has the ability to change an item onto a certain axis in these circumstances. This is referred to as the force's turning effect. 

Simply put, we say that a body is in motion anytime it is in motion. We may say that a boy is moving, for instance, if he is going from the school to his house along the street. But consider if a boy took a five-minute break from driving and sat down. If someone inquires right away as to whether the boy is moving, the response will be "no."

Motion and force are fundamental to nature. We can state that movement is caused by force. If there is a movement, we can infer that there must be a force at play or that this movement is produced by a force. There must be an active force at work while a person is walking, which constitutes motion. This force, what is it? His body's muscular power is represented by this force. Movement is the general phrase for physical activity. Motion can generally be described as,

Change the direction, not the speed, though.

From Newton’s second law of motion, we can define the relationship between force and motion mathematically as:

F = m.a

Thus, force is defined as the product of mass and acceleration.