Question

A body covers a distance of 4 m in `3^(rd)` second and 12m in `5^(th)` second. If the motion is uniformly accelerated. How far will it travel in the next 3 seconds?
A. 10 m
B. 30 m
C. 40 m
D. 60 m

Answer 1

Correct Answer - D
`S_3 = u + a/2(2 xx 3 - 1) = 4` or `u + 5/2a = 4`
`S_5 = u + a/2(2 xx 5 - 1) = 12` or `u + 9/2 a = 12`
On solving, `u = -6 m s^(-1)`, a = `4 m s^(-2)`
Distance travelled in next 3 seconds = `S_8 - S_5`
`[-6 xx 8 + 1/2 xx 4 xx(8)^(2)] - [-6 xx 5 + 1/2 xx 4 xx (5)^(2)]`
80 - 20 = 60 cm