7.A body attains a velocity of 25m/s in 2s with an acceleration of 4m/s2.The displacement of the body is

solution:

final velocity:25m/s

time :2s

a=4m/s2

then, the formula we have

v=u+at

25=u+4*2

25-8=u

u=17m/s

The displacement S=ut+1/2at2

S=17(2)+1/2(4)(2)(2)

S=34+8

S=42m

The displacement of the body is 42m