Question

A car is moving with speed of 108km/hr on a straight road decreases its speed to 90 km/hr in 5 sec Find the displacement of the car in last second of moving before it comes to hault​

Answer 1

Explanation:

velocity(u)=90km/h.

=25m/s

finalvelocity(v)=36km/h

=10m/s

time(t)=5s.

acceleration (a)=

t

v−u

=

5

10−25

=

5

−15

= −3m/s

2

let,

Using the third equation of motion

2as=v

2

−u

2

2(−3)(s)=(10)

2

−(25)

2

−6s=100−625

−6s=−525

6s=525

s=

6

525

=87.5m