Efficiency of cyclist when he does 12 J of useful work from every 100 J of food energy he takes is
(required form of output/total input energy)×100 is equal to
If we place some coins over paper strip and pull it with a jerk, then coins don't falloff because of
Density of metal spoon when its weight in air is 0.48 N and in water is 0.42 N is
Earth's gravitational force of attraction vanishes at
A wooden cube of sides 10 cm each dipped in water. upthrust of water would be
Ratio of required form of energy obtained from a system as output to total energy given to it as input is called its
A bullet of mass 30 g is fired from a gun with a muzzle velocity 90ms-1. If its mass is 4 kg then recoil of gun will be