Question

Which law of conservation is used in the working of rockets?

Answer 1

Momentum

1. The product of the mass of an object to its velocity is termed as momentum.
2. The conservation law of momentum states that in a closed system the total momentum of the system remains constant.
3. For example, if the gun is fired, the direction of the shooting of a bullet and the direction of recoiling are opposite to each other. If a bullet is fired from a gun, both the bullet and the gun are initially at rest i.e. the total momentum before firing is zero. The bullet acquires a forward momentum when it gets fired. According to the conservation of momentum, the gun receives a backward momentum.
4. Thus, one momentum is positive and one is negative, making the total change zero.

1. Rockets have a gas chamber at one end, from which gas is ejected with enormous velocity. Before the ejection, the total momentum is zero. Due to the ejection of gas, the rocket gains a recoil velocity and acceleration in the opposite direction. This is a consequence of the conservation of momentum
2. When the rocket engine is ignited the gases are expelled at a huge velocity in a downward direction hence giving the rocket equal momentum to move upward in space.
3. The momentum of gases is equal to the momentum of a rocket but they are opposite to each other, hence they are balanced.