The Total solution for NCERT class 6-12
State if each of the following statements istrue or false. Give reasons for your answer.(a) In an elastic collision oftwo bodies, the momentum and energy of each body is conserved.(b) Total energy of a system isalways conserved, no matter what internal and external forces on the bodyare present.(c) Work done in the motion of abody over a closed loop is zero for every force in nature.(d) In an inelastic collision,the final kinetic energy is always less than the initial kinetic energy of thesystem.
(a) False, the total momentum and total energy of the system areconserved.(b) False, the external force on the system may increase or decrease the totalenergy of the system.(c) False, the work done during the motion of a body over a closed loop is zeroonly when body is moving under the action of a conservative force (such asgravitational or electrostatic force). Friction is not a conservative forcehence work done by force of friction (or work done on the body againstfriction) is not zero over a closed loop.(d) True, usually in an inelastic collision the final kinetic energy is alwaysless than the initial kinetic energy of the system.