Question

a body is moving with uniform acceleration describes 40 m the first 5 sec and 65 m in the next 5 sec.find the initial velocity

Answer 1

Let ‘u’ be the initial velocity, ‘a’ be the acceleration.

In first 5 s it moves 40 m, so,

S = ut + ½ at2

=> 40 = 5u + ½ a(52)

=> 8 = u + (5/2)a ………………(1)

Next, it travels 65 m in (5 + 5 =) 10 s, so,

65 = 10u + ½ a(102)

=> 13 = 2u + 10a ………………(2)

So, u = 19/2 m/s, a = -3/5 m/s2

So, initial velocity is, u = 19/2 m/s.