Motion Case

Motion

Scalar quantity: a physical quantity having only magnitude and no specified direction. E.g. mass, length, temperature, time, energy, speed, area, distance.

Vector quantity: a physical quantity having both magnitude and a specified direction. E.g. displacement, velocity, momentum, weight, acceleration, force.

Distance: distance travelled by an object is the length of the actual path travelled by the object during motion.

Displacement: it is a change in the position of the object in a particular direction, or, it is the shortest distance between the initial and the final position of the object.

Speed: it is the distance travelled by the body in unit time.

Speed= Distance travelled

Time taken

v= s m/s

t

Velocity: rate of change of displacement with respect to time, or, distance travelled by a body in unit time and in a given time.

Average velocity= v+u

2

Acceleration: rate of change of velocity of the body with respect to time.

a= v-u m/s2

t

Newton's first law of motion:

Everybody continues to be in a state of rest or of uniform motion along a straight line unless it is compelled by an external force to change that state.

Inertia of a body is the inability of the body to change its state of rest or of uniform motion along a straight line.

Newton's first law of motion is also called the law of inertia.

Momentum: momentum of a body is defined as the capacity of the body for imparting velocity to another body and is measured as the product of mass of the body and its velocity.

Newton's second law of motion:

The rate of change of momentum of a body is directly proportional to the force acting on it and takes place in the direction of force.

Newton's third law of motion:

To every action there is always an equal and opposite reaction.