Total momentum of two bodies remains unchanged before and after the collision. Justify this statement.

Underline the correct alternative :- In an inelastic collision of two bodies, the quantities which do not change after the collision are the total kinetic energy//total linear momentum//total energy of the system of two bodies.

Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement taking any two examples.

Trophical regions are likely to have more biological diversity than temperate ones. Give two reasons to justify the statement.

A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m s^-1 to 3.5 m s^-1 in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force ?

Sewage Treatment Plants (STPs) are those plants where sewage water is treated before its discharge into the rivers. Discuss the following: Sewage treatment provides not only usable water but also generates fuel. Justify the statement.

If the charge distribution within Gaussian surface is changed, but total charge inside it remains unchanged, will there be any change in the electric field strength outside inside the Gaussian surface?

When brakes are applied in a car,the brake-shoes apply frictional force on the wheels.these forces are internal for the system(car).For retardation,external forces ust act on the system.The force of friction at the road surface remains the same before and after teh brakes are applied (f = mu N) .How does the car stop?