#1 A long jumper runs before jumping because he
An athlete runs before jumping to gain momentum. Because it helps in jumping higher and longer because of inertia of motion gained due to the motion.
#2 A body is thrown vertically upwards and then falls back on the ground. Its potential energy is maximum
We know that Potential energy = mgh
#3 A jet engine works on the principle of conservation of
A jet engine works on the principle of conservation of linear momentum. In jet engines, a large volume of gases produced by the combustion of fuel is allowed to escape through a jet in the backward direction.
#4 One feels heavier in a lift when the lift
One feels heavier in a lift when the lift just begins to go up because our body gains inertia from the position of rest and pushes up against the gravity so here the weight becomes zero and our mass makes us feel heavier.
#5 The lift of an air plane is based on
Aerodynamics are taught that airplanes fly as a result of Bernoulli’s principle, which says that if air speeds up the pressure is lowered. Thus a wing generates lift because the air goes faster over the top creating a region of low pressure, and thus lift.