Physics Past Questions and Answers

A piece of substance of specific heat capacity 450Jkg\(^{-1}\)k\(^{1}\) falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms\(^{-2}\)]<br/>

I. A liquid boils when its saturated vapor pressure is equal to the external pressure<br/>II. Dissolved substances in pure water lead to an increase in the boiling point.<br/>III. When the external pressure is increased, the boiling point increases.<br/>IV. Dissolved substances in pure water decreases the boiling point <br/><br/>Which of the above combinations are peculiarities of the boiling point of a liquid?

A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is?

A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms\(^{-1}\) from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is? (Take g = 10ms\(^{-2}\))

A car of mass 800kg attains a speed of 25m/s in 20secs. The power developed in the engine is?