Duduli

Answer:- A collision is said to be perfectly inelastic collision if in collision the particles stick permanently together on impact and the loss of kinetic energy is maximum consistent with the requirements of conservation of momentum.

Answer:- A collision is said to be an elastic collision if the sum of the kinetic energies of the particles after collision is  same as the sum of kinetic energies before collision.

Answer:- Potential energy per unit area of the surface of fluid is called surface energy.

Answer:- Radius of gyration of a body about an axis is that distance, at which  if whole of the mass of the body were concentrated, it would have same moment of inertia as that of body.[I=MK²].   Where,K= Radius of gyration or effective distance or the radius of the centre of mass of that body.                        

Answer:- If in a very small time interval their is a large torque applied on a body then the change in angular momentum of that body is known as angular impulse.(Vector quantity) As,

Answer:- A rigid body is said to be in equilibrium if   it do not change its state of rest or  uniform motion (linear or rotational) with respect to time. ★If ,    F(external)=0 it implies translatory equilibrium. ★If,      Torque (external)=0 it implies rotatory equilibrium.

Answer:- A system of coordinate axes which defines the position of a particle or an event in two or three dimensional space is called frame of reference. ★The simplest frame of reference is Cartesian system of coordinates.

Answer:- A frame of reference is said to be inertial   frame of reference either it move with constant velocity or is at rest with respect to a fixed frame. ★In inertial frame Newton's laws are valid.

Answer:- A rigid body is defined as a solid body in which the particles are compactly arranged so that the inter-particle distance is small and fixed and is not disturbed by any external forces applied.