Question

A particle experiences constant accelaration for 20secs after starting from rest.If it travels a distance s1 in the first 10secs ad distance s2 in the next 10secs then, (a) s2=s1 (b)s2=2s1 (c)s2=3s1 (d)s2=4s1?

Answer 1

s=ut+12a(t^2)

u=0 m/sec          (body starts from rest)

s1=1/2a(t^2)

s1=1/2a(10^2)

s1=50a ------------------(1)

now initial velocity for s2 is the final velocity of s1

let final velocity of s1=initial velocity of s2=v

so, v=u +at

  v=at

  v=10a  (since u=0 and t=10)

now s2=ut+1/2a(t^2)

s2=(10a)10+1/2a(10^2)

s2=100a+50a

s2=150a -------------------------(2)

now

(2)/(1)=s1/s2

S1/s2=50a/150a

3s1=s2