Question

A body is thrown vertically upwards with an initial velocity of 19.6 m/s. If accelaration due to gravity $g=9.8m/s^2$. Calculate the following:
(i) The maximum height attained by the body.
(ii) The time to reach the ground. [5 MARKS]

Answer 1

Maximum height : 2.5 Marks
Total time : 2.5 Marks

(i) Given
$u=19.6m/s,g=–9.8m/s^2,v=0$
$Usingequation{v}^2=u^2+2as,weget$
$0={19.6}^2+(2\times (–9.8)\times h)$
$h=19.6m$

(ii) Time taken to reach the maximum height can be calculated by the equation,
$v=u+gt$
$0=19.6+(–9.8\times t)$
t = 2 s
In the same time, it will come back to its original position.
Total time = $2\times 2=4s$