Question

The bullet fired from the gun gets heated on striking a target because:
A) It losses energy
B) Mechanical energy gets converted to heat energy
C) of latent heat
D) Specific heat

Answer 1

Hint: The above problem is based on the first law of thermodynamics:
“Energy can neither be created nor be destroyed”. Energy conversion will take place when a bullet will be fired from the gun. Keeping in mind the above stated law we state the reason for the heated bullet in more detail.

Complete step by step solution:
When a bullet is fired from the barrel of the gun it faces frictional energy in the barrel itself because of tight packing for better propulsion, the bullet gets slight heating in the barrel itself. When a bullet moves through the air it gains kinetic energy and releases some of the kinetic energy to the air friction. When the bullet hits the target, the target and bullet both get deformed and the kinetic energy of the bullet gets converted to heat energy.

We can cite an example which we all have seen or done in our day to day lives is that when we hit the nail with a hammer at the desired place; on several hits our hammer as well as nail gets heated up because of the conversion of kinetic energy of hammer into heat energy.

Thus, option (B) is the most appropriate reason.

Note: There are various other forms of energy conversion takes place which we all observe everyday such as when lights bulb lights up electrical energy is converted into heat and light energy, kinetic energy of falling water on the turbines in the hydro power station gets converted into electrical energy, starting of generated we provide the manual work to start the generator by moving its handle that mechanical energy gets transformed to electrical energy.