Question

A body
is initially moving

at constant rate
with velocity of 18 km/h
which starts decelarating at constant rate of
2m/s? Determine the time at which body becomes
stationary. Also and the distance​

Answer 1

Explanation:

u=5m/s

a=-2m/s²

v=0m/s

t=-5/-2=2.5sec

Answer 2

Answer: Time= 9 sec  ; distance=81 m

Explanation:

Final velocity = 0

Initial velocity= 18m/s    ; acceleration= -2ms⁻²

Now,   v=u+at

⇒ 0 = 18 +(-2)t

⇒18 = 2t  ⇒t = 9

∴ time= 9 sec

Also, v² = u² + 2as

⇒ 0= (18)² + 2(-2)s

⇒ 324 = 4s

⇒ s = 324/4      ∴s= 81

∴ Distance= 81m

( you can also find distance using s= ut + 1/2at²)