A jet engine works on the principle of conservation of

Question

Question

This question was previously asked in

ISRO URSC Technical Assistant Mechanical 13 Nov 2016 Official Paper

Answer 1

CONCEPT:

Momentum: Momentum is the product of the mass and the velocity of an object or particle. It is a vector quantity.
- The standard unit of momentum magnitude is the kilogram-meter per second (kg·m/s).

P = m v

Where P = momentum, m = mass of the body, v = velocity of body.

Conservation of Linear Momentum: Conservation of Linear Momentum states that a body in motion retains its total momentum (product of mass and vector velocity) unless an external force is applied to it.
In mathematical term

Initial momentum = Final momentum

P_i = P_f

EXPLANATION:

The Jet engine works on the phenomenon of Conservation of Linear Momentum.
It produces a large volume of gases through the combustion of fuel, which is allowed to escape in backward direction through a jet.
The backward rushing gas gains large momentum because of high velocity.
It thus imparts an equal and opposite momentum to the jet engine.
The jet engine, thus, moves forward with high speed. So option 1 is correct.