* Question 1: *Velocity of a car increases uniformly at the rate of 5 ms

^{-1}and after 10 s becomes 45 ms

^{-1}. Find the acceleration of the car.

**Solution**

Here,

initial velociti u = 5ms^{-1}

final velociti v = 45ms^{-1}

time t = 5s

acceleration a = ?

We know,

**a = (v – u)/t**

or, a = (45 ms^{-1} -5 ms^{-1})/5s

= 40 ms^{-1} / 5s = 8 ms^{-2}

Ans : 8 ms^{-2}

* Question 2: *The Velocity of a car decreases uniformly from 20 ms

^{-1}and after 4s it becomes 4 ms

^{-1}. Find the acceleration of the car.

**Solution**

Here,

initial velocity u = 20 ms^{-1}

final velocity v = 4 ms^{-1}

time t = 4 s

acceleration a = ?

We know,

**a = (v – u)/t**

or, a = (4 ms^{-1} – 20 ms^{-1})/4 s

= – 16 ms^{-1} / 4 s = – 4 ms^{-2}

Ans : – 4 ms^{-2}