# Physics

Mechanics is the oldest branch of physics. Mechanics deals with all kinds and complexities of motion. It includes various techniques, which can simplify the solution of a mechanical problem. Here are some of the often required physics formulas falling in mechanics domain.

Motion in One Dimension

The physics formulas for motion in one dimension (Also called Kinematical equations of motion) are as follows. (Here 'u' is initial velocity, 'v' is final velocity, 'a' is acceleration and t is time): * s = ut + ½ at2

* v = u + at

* v2 = u2 + 2as

* vav(Average Velocity) = (v+u)/2

Momentum, Force and Impulse

Physics Formulas for momentum, impulse and force concerning a particle moving in 3 dimensions are as follows (Here force, momentum and velocity are vectors ): * Momentum is the product of mass and velocity of a body. Momentum is calculate using the formula: P = m (mass) x v (velocity) * Force can defined as something which causes a change in momentum of a body. Force is given by the celebrated newton's law of motion: F = m (mass) x a (acceleration) * Impulse is a large force applied in a very short time period. The strike of a hammer is an impulse. Impulse is given by I = m(v-u) Pressure

Pressure is defined as force per unit area:

| | Pressure (P) = | Force (F)Force (A)| |

Density

Density is the mass contained in a body per unit volume.

The physics formula for density is:

| | Density (D) = | Mass(M)Volume (V)| |

Angular Momentum

Angular momentum is an analogous quantity to linear momentum in which the body is undergoing rotational motion. The physics formula for angular momentum (J) is given by:

J = r x p

where J denotes angular momentum, r is radius vector and p is linear momentum.

Torque

Torque can be defined as moment of force. Torque causes rotational motion. The formula for torque is: τ = r x F, where τ is torque, r is the radius vector and F is linear force.

Circular Motion

The physics formulas for circular motion of an object of mass 'm' moving in a circle of radius 'r' at a tangential velocity 'v' are as follows: | | Centripetal force (F) = | mv2r| |

| | Centripetal Acceleration (a) = | v2r| |

Center of Mass

General Formula for Center of mass of a rigid body is :

| | R = | ΣNi = 1 miriΣNi = 1mi| |

where R is the position vector for center of mass, r is the generic position vector for all the particles of the object and N is the total number of particles.

Reduced Mass for two Interacting Bodies

The physics formula for reduced mass (μ) is :

| | μ = | m1m2m1 + m2| |

where m1 is mass of the first body, m2 is the mass of the second body.

Work and Energy

Physics formulas for work and energy in case of one dimensional motion are as follows:

W (Work Done) = F (Force) x D (Displacement)

Energy can be broadly classified into two types, Potential Energy and Kinetic Energy. In case of gravitational force, the potential energy is given by

P.E.(Gravitational) = m (Mass) x g (Acceleration due to Gravity) x h (Height) The transitional kinetic energy is given by ½ m (mass) x v2(velocity squared)

Power

Power is, work done per unit time. The formula for power is given as | | Power (P) = | V2R| =I2R| |

where P=power, W = Work, t = time.

Physics Formulas: Friction

Friction can be classified to be of two kinds : Static friction and dynamic friction.

Static Friction: Static friction is characterized by a coefficient of static friction μ . Coefficient of static friction is defined as the ratio of applied tangential force (F) which can induce sliding, to the normal force between surfaces in contact with each other. The physics formula to calculate this static coefficient is as follows: | | μ = | Applied Tangential Force (F)Normal Force(N)| |

The amount of force required to slide a solid resting on flat surface depends on the co efficient of static friction and...

Please join StudyMode to read the full document