Rectilinear Motion

Short physics notes

1. RECTILINEAR MOTION
Motion is a property of combined observer and observedparticle.
Position
Displacement
Distance
Average Velocity <> = = direction of average velocity is always in the
direction of displacement.
Average Speed <V>= ; Average speed is never less than average
velocity.
Average accretion<> = =.

Q. Aparticle covers one half path with speed V1 and next half with speed V2 then find the
average speed of particle.
Q. Aparticlehaving speed V1for half timeand V2for next half time. Find the average speed of
particle.
Q. A car goes toward a tree with speed 60 km/h. One crow go to tree from car with speed 90
km/h and then come back to car and again go to tree and repeat this motion. The initial
distance between car and tree is 240 km. find the distance covered by the crow during car
reach to tree.
Q. A ball stickera wall with speed 10 m/s and return back with same speed. Find the average
accretion.

Equation of Motion (only for constant accretion)
i> v=u+at
ii> s =()t
iii> s =ut+at
2

iv> s =vt-at
2

v> v
2
=u
2
+2as
vi> sn=u+a(2n-1); [displacement in n
th
second]
Q. A particle covers 10m distance in 2sec. If final velocity is 8m/s then find initial velocity.
Q. Speed of a man toward a bus is 6m/s and accretion of that bus is 1m/s
2
. If initial distance
between man and bus is 10m then will then man catch the bus?
Q*. A car is going with speed 20m/s. Car take break to stop and generate 5m/s
2
deaccretion.
Find the displacement of car during 6 sec. ans: 40 m
Rest: graph