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 

(1) 4 m/s

(2) 2.5 m/s

(3) 5.5 m/s

(4) 11 m/s 

Concept Videos :-

#26-Equations-for-Uniform-Acceleration
#27-Equations for Uniform Acceleration 28Calculus Method29
#28-Sign Convention
#29-Solved Examples 16
#31-Solved-Examples-18
#32-Solved Examples 19
#33-Solved Examples 20
#34-Solved-Examples-21
#35 Solved Examples 22
#30-Solved Examples 17

Concept Questions :-

Uniformly accelerated motion

(3) S1=ut+12at2   .....(i)

and velocity after first t sec

v=u+at

Now, S2=vt+12at2

=(u+at)t+12at2  ..... (ii)

Equation (ii) – (i) S2S1=at2

a=S2S1t2=6540(5)2=1m/s2

From equation (i), we get,

S1=ut+12at240=5u+12×1×25

5u=27.5    u=5.5m/s     

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