Physics

The ratio of the amount of work done by a machine and total given energy is called efficiency of that machine.

The capacity of doing work that is acquired by a moving body due to its motion is called kinetic energy. In everyday language, energy means a capacity for activities and hard work. Likewise, in physics, energy is a capacity for performing work. Energy is “stored” work, which can be converted into actual work under suitable … Read more

The mass per unit volume of a substance is caused by the density of its material. or,  The mass of an object per unit volume is the density of the object.

Work is the product of applied force on a body and its displacement along the direction of force.

Energy has no creation or destruction, it transforms only from one form to another form. The total energy of the universe is defined and not changeable.

The main source of energy is sun.

The amount of work done or energy expended per unit of time is called power. The algebraic expression for power is Where ΔW is the energy expended in a time interval Δt. The SI unit of power is called the watt (W) and it is defined as a rate of transfer of energy of 1 … Read more

The physical quantity which is produced by the scalar product of the mass and the velocity of a moving body is defined as its momentum. Momentum is this product of mass multiplied by its velocity. Momentum = Mass x Velocity. Momentum is also a vector quantity. If the velocity increases, momentum also increases. When two bodies, … Read more