Question

The speed of an vehicle changes from 80 km/hr to 60 km/hr in 5 sec.
Find the acceleration (a) of the vehicle?

Pls solve it fast >>>...

Answer 1

r = -a

r= [initial velocity (u) - final velocity (v)]/time (t) = (u-v)/t

But all of them should be in the same units, as it doesn’t make sense to convert 5sec to hours, lets convert kmph to mps

1 Kmph = 5/18 mps

so u = 90kmph = 90 * 5/18 mps = 25 mps

and v = 36 kmph = 36 * 5/18 mps = 10 mps

time t = 5s

r = (25–10)/5 = 3 m/s^2

and distance traveled in that time s = ut - (1/2)(rt^2) = 25*5 - (3/2)(5*5)

==> s = 125 - 37.5 = 87.5 meters or 0.0875 kms
nto m/s,

90 km/h = (90*1000 m)/3600 s

= 25 m/s

36 km/h = (36*1000 m)/3600 s

= 10 m/s

There is an equation,

Distance = (1/2)(Initial Speed+Final Speed)(Time)

= (1/2) * (25+10) * 5 m

= 87.5 m

87.5 m distance will cover in 5 sec

Answer 2

hello here is your answer
(^-^) (^-^)

initial velocity= 80km/hr

final velocity= 60km/hr

converting it into m/s

80×5/18
4.44×5
= 22.2m/s

and 60×5/18
= 16.65m/s

acceleration = v-u/t
so, 16.65-22.2/5
= -5. 55/5
= -1.11m/s^2

answer -1. 11m/s^2


hope it helps