Question

-
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
(a) 4 m/s
(b) 2.5 m/s
(c) 5.5 m/s
(d) 11 m/s​

Answer 1

$\bf\large\underline\blue{Answer:-}$

c)5.5 m/s

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We know that

S =ut+1/2 at(square)

Firstly

40=u5+1/2a×25

8=u+5/2a

By multiply 2 both side

16=2u+5a.........eq(1)

Now 2nd portion

40+65=105m total distance covered in 10 sec

105=10u+1/2a×100

Divide by 5 on both side

21=2u+10a.........eq(2)

Now

16=2u+5a ×2......eq(1)

21=2u+10a ×1.......eq(2)

On substraction eq(1)-eq(2)

We get

11=2u

U=11/2

U=5.5 m/s