A bus decreases its speed from $80 \mathrm{km}/\mathrm{h}$ to $60 \mathrm{km}/\mathrm{h}$ in $5 \sec$. Find the acceleration of the bus.

 Find the initial velocity of a car which stops in $\mathrm{}$ 10 \sec $$ after applying brakes at the rate of $\mathrm{}$ 2 \mathrm{m}/{\mathrm{s}}^2${\mathrm{}}^{}$. 

A ball initially moving at a speed of $25 \mathrm{m}/\mathrm{s}$ is acted upon by a constant retardation of $2.5 \mathrm{m}/{\mathrm{s}}^2$. For how long will the ball roll, before coming to rest?                                      

Draw the velocity-time graphs for the following situations:

(a) When the body is moving with a uniform velocity.

(b) When the body is moving with a variable velocity and uniform acceleration.

(c) When the body is moving with a variable (non-uniform) velocity and uniform deceleration.

(d) When the body is moving with a variable velocity and variable acceleration.

From the diagram calculate

(i) acceleration

(ii) retardation

(iii) distance covered in first 8 seconds

(iv) total distance travelled by the body and

(v) average velocity in the region ACB.