Question

If a car at rest accelerate uniformly and attains a speed of 54km/h in 10 sec it covers a distance of ________ ?

Answer 1

We have V=u + at
Final speed v = 54 km/ hr = (54×1000/60×60) m/s = 15 m/s
[ converting from km/hr to m/s]
Initial speed u = 0
Time t = 10 sec
Substituting v,u and t in the first equation we get,
15 = 0 + a×10
=> 15 = 10a
a=15/10 =1.5 m/s^2

We know
Distance S = ut + (1/2)at^2
U =0
t = 10 s
a= 1.5 m/s^2
So S = 0 + 0.5×1.5×10^2
= 75 m