Question

A bus of mass 5000 kg starts from rest and rolls down a hill. If it travels a distance of 200m in 10 sec, calculate the acceleration of bus and force acting on the bus.

Answer 1

Given,

Mass of ball = 5000 kg

Distance travelled = 200 m

Time taken = 10 sec

To Find,

The acceleration of bus and force acting on the bus.

Solution,

We need to use the equations of motion in order to solve this question.

u = 0

s = 200m

t = 10 sec

s = ut+1/2 at²

200 = 1/2 a 100

a = 4 m/s²

Now,

Force = mass * acceleration

          = 5000*4

          = 20,000 N

Hence, the aceeleration of bus is 4m/s² and the force acting on the bus is 20,000 N.

Answer 2

Answer:

The acceleration and force acting on the bus are 4m/s² and 20kN respectively

Explanation:

From the second equation of motion we have,

$S=ut+\frac{1}{2}at^2$       (1)

Where,

S=distance traveled by the body

u=initial velocity of the body

t=time taken to travel the distance

a=acceleration of the body

From the question we have,

M=5000kg

S=200m

t=10s

u=0       (∵ the body starts from rest)

By substituting the required values in equation (1) we get;

$200=0\times 10+\frac{1}{2}a\times (10)^2$

$a=\frac{200\times 2}{100}=\frac{400}{100}=4m/s^2$               (2)

The force(F) acting on the body is given as,

$F=ma$             (3)

By substituting the value of mass and acceleration in equation (3) we get;

$F=5000\times 4=20000=20kN$

Hence, the acceleration and force acting on the bus are 4m/s² and 20kN respectively.