Home
Class 12
PHYSICS
A body starts from rest and travels a di...

A body starts from rest and travels a distance `S` with uniform acceleration, then moves uniformly a distance `2S` uniformly , and finally comes to rest after moving further `5S` under uniform retardation. The ratio of the average velocity to maximum velocity is.

Text Solution

Verified by Experts

Graphically:Area of (V-t) curve represent displacement

`S=1/2V_"max"t_1` or `t_1=(2S)/V_"max"`
`2S=V_"max"t_2` or `t_2=(2S)/V_"max"`
`5S=1/2 V_"max"t_3` or `t_3=(10S)/V_"max"`
`V_(av)="Total displacement"/"Total time"`, `V_"av"=(S+2S+5S)/("2S"/V_"max"+"2S"/V_"max"+"10S"/V_"max")`
`V_(av)/V_"max"=(8S)/(14S)=4/7`
`V_(av)/V_(max)="Total displacement"/(2("total displacement during acceleration and retardaton")+("Displacement During uniform velocity "))`
`therefore V_"av"/V_"max"="8S"/(2(S+5S)+2S)=8/14=4/7`
Promotional Banner

Topper's Solved these Questions

  • MOTION IN A STRAIGHT LINE

    AAKASH SERIES|Exercise EXERCISE -I|58 Videos

  • MOTION IN A STRAIGHT LINE

    AAKASH SERIES|Exercise EXERCISE -II|80 Videos

  • MOTION IN A PLANE

    AAKASH SERIES|Exercise QUESTION FOR DESCRIPTIVE ANSWER|7 Videos

  • MOVING CHARGES AND MAGNETISM

    AAKASH SERIES|Exercise EXERCISE-III|49 Videos

Similar Questions

Explore conceptually related problems

A body starts from rest and travels a distance S with unitorm acceleration, then moves uniformly a distance 2S uniformly , and finally cones to rest after moving further 5S under uniform retardation. The ratio of the average velocity to maximum velocity is.

A particle starts from rest and traverses a distance l with uniform acceleration, then moves uniformly over a further distance 2l and finally comes to rest after moving a further distance 3l under uniform retardation. Assuming entire motion to be rectilinear motion the ratio of average speed over the journey to the maximum speed on its ways is

A body starts from rest and then moves with uniform acceleration. Then.

A body starts from rest and travels a distance x with uniform acceleration, then it travels a distance 2x with uniform speed, finally it travels a distance 3x with uniform retardation and comes to rest. If the complete motion of the particle is along a straight line, then the ratio of its average velocity to maximum velocity is

A train takes t sec to perform a journey , if travel for t/n sec with uniform acceleration then for ((n-3)/(n))t sec with uniform speed v and finally it comes to rest with uniform retardation. Then average speed of train is

A body starts from rest and moves with a uniform acceleration. The ratio of the distance covered in the nth sec to the distance covered in n sec is

A body starts from rest and acquires a velocity 10 m s^(-1) in 2 s. Find the acceleration.

A car starts from rest and moves with uniform acceleration for time t then it moves with uniform speed of 60 km/h for time 3t and comes to rest. Find the average speed of car in its total journey.

A body starting from rest is moving with a uniform acceleration of 8m/s^(2) . Then the distance travelled by it in 5th second will be

A body starts from rest with a uniform acceleration of 2 m s^(-1) . Find the distance covered by the body in 2 s.