Question

A body starts moving by a straight line with a con stant acceleration of 4 m/s2. The distance it trav els in the fifth half second is (1) 4.5 m (2) 8 m (3) 9 m (4) 18 m

Answer 1

Considering the body to start from rest u = 0 m/s

Given, Acceleration of the body = 4 m/s^2

The formula is,

$\sf S_{n} = Distance \: travelled \: in the \: nth \: second \\ \\ \sf S_{n} = u + a ( n - \frac{1}{2} )$

So, To find the distance travelled in the 5th half second, n = 5 (1/2) = 5/2

Now,

$\sf S_{ (\frac{5}{2})}= 0 + 4 ( \frac{5}{2} - \frac{1}{2} ) \\ \\ S_{ (\frac{5}{2})} = 4( \frac{4}{2} ) = 4 \times 2 = 8m$

Therefore,

Therefore,The distance travelled in the 5th half second is, 8m.