01.1 SOME DEFINITIONS
(a) Distance: Distance between two points is the length of actual path travelled by the particle. It is a scalar quantity.
Unit : m(metre)
(b) Displacement: Displacement is change in position vector of a particle. It is a vector quantitiy.
Unit : m(metre)
Velocity: Velocity is the rate of change of position vector. It is a vector quantity.
Unit : ms–1 (metre per second)
(d) Acceleration: Acceleration is the rate of change of velocity.
Unit : ms–2 (metre per second2)
(e) Average speed: Average speed is total distance travelled divided by total time taken.
(f) Average velocity: Average velocity is total displacement divided by total time taken. The direction of average velocity is direction of displacement.
(g) Average acceleration : Average acceleration is total change in velocity divided by total time taken. The direction of average acceleration is direction of change in velocity.
(h) Uniform velocity: A particle with uniform velocity undergoes equal displacements in equal intervals of time however small the intervals may be.
(i) Uniform acceleration: A particle with uniform acceleration undergoes equal changes in velocity in equal intervals of time, however small the intervals may be.
