Question

Q2-a body is moving with a speed of 40km/h.one second later.it is moving at 58km/h? What is it's acceleration

Answer 1

hello , 
as you know , 
a = v-u / t 
here,
u = 40 km / hr = 11.1 m/s 
v = 58 km / hr = 16.1 m/s 
t = 1 second 
so , a = 16.1 - 11.1 / 1 =  05.0 m /s = 5 m/s 
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Answer 2

Initial speed=u=40km/h =40 x 5/18=11.1m/s
Final speed=v=58km/h =58x5/18=16.1m/s
Time=t=1sec
acceleration=a=?

a=(v-u)/t
=(16.1-11.1)/1
=05.5 m/s^2
=5 m/s^2