Question

A car is moving at a speed of of 18km/hr. It starts retarding uniformly at 1m/s square and comes to rest. Find distance travelled

Answer 1

given..
u-18km/h=18×5/18=5m/s
a--1m/s square
v-0m/s
t=?
s=?
So..
v=u+at
0=5+(-1)×t
0=5-t
5 seconds=t

now..
s=ut+1/2at square
s=5×5+1/2×(-1)×25
s=25-25/2
s=50-25/2
s=25/2
s=12.5m

Answer 2

Answer: 12.5m

Explanation:

u=18km/h

= 5m/s

a = -1m/s

v = 0m/s (comes to rest )

So,

v =u +at

0=5+(-1)×t

0=5-t

t= 5 seconds

Now,

Distance travelled (s)

2as =v^2 - u ^2

2 (-1) s = (0)^2 -(5)^2

-2 s = -25

s =-25/-2

s = 12.5m

Hope it will help someone ...someday ..