A body is moving with uniform acceleration describes 40 m in the first 5 sec and 65 m in next 5 sec. Its initial velocity will be

Options

A. 4m/s
B. 2.5m/s
C. 5.5m/s
D. 11m/s

Answer

C

Explanation

`S=ut+(1)/(2)at^(2)`
`40=5u+a((25))/(2)`
`S=40+65=105`
t=5+5=10s
`S=ut+(1)/(2)at^(2)`
`10j6=10u+(1)/(2)a(100)`
From equation (i) `xx4-(ii)`
`160=20u+(1)/(2)a(100)`
`-105=10u-(1)/(2)a(100)`
`55=10u`
`u=5.5m//s`