Question

A body is moving with uniform acceleration describe 40m in first 5second and 65m in next 5second. It's initial velocity will be?

Answer 1

You have

5v + a/2 * 5^2 = 40
10v + a/2 * 10^2 = 105

Now just solve for v.

Answer 2

Help full for problems

Answer 3

5v + a/2 * 5^2 = 40 ____ (i)
10v + a/2 * 10^2 = 10^2 ____ (ii)
for (i) :
80 = 10v +25a
16 = 2v +5a _____ (a)
for (ii) :
105 = 10v + 100a/2
105 = 10v + 50a
21 = 2a + 10a _____ (b)
solve for( a )&( b )
we get ,
5a = 5
a=1
therefore :
2v +5=16
2v = 11
v = 5.5m/s

Answer 4

If initial velocity be u and the acceleration be a then the distance in first 5s will be S
5
​
=u(5)+
2
a(5)
2

​
=40m........(1)
and the distance in first 10s will be S
10
​
=u(10)+
2
a(10)
2

​

so the distance between time t=5s to t=10 will be
S
5
′
​
=S
10
​
−S
5
​
=65m ...........(2)
putting corresponding values and solving the equation-1 and equation-2 we get u=5.5m/s
Option C is correct.