Motion
Physics · गति · 15 facts
Motion: change in position of an object with respect to time and surroundings
Distance: total path length (scalar); Displacement: shortest path start to end (vector)
Speed = distance/time (scalar); Velocity = displacement/time (vector)
Acceleration = rate of change of velocity; unit = m/s2
Uniform motion: equal distance in equal time intervals; velocity is constant
Non-uniform motion: unequal distance in equal time; acceleration is non-zero
Equations of motion: v=u+at; s=ut+0.5at2; v2=u2+2as
Free fall: acceleration = g = 9.8 m/s2; all objects fall at same rate in vacuum
Circular motion: direction changes continuously so velocity changes even if speed constant
Centripetal force directed toward centre of circle; F = mv2/r
Projectile motion: combination of horizontal (uniform) and vertical (accelerated) motion
Maximum range of projectile at 45 degree launch angle
Retardation (deceleration): negative acceleration, object slowing down
Average speed = total distance / total time; may differ from average velocity
Displacement can be zero even if distance is not (returning to start point)