Question

A ball is thrown vertically upwards. when the ball reaches one half of its maximum height, its speed becomes 10m/s
(a) How high does the ball rise?
(b) Find the velocity and acceleration 1s after it is thrown.

Answer 1

As we know,

(a)

$\left(100\right)-u^2=2g{h}^{\prime }$

$andwealsoknow,\left(0\right)-u^2=-2gh$

$so,100-2gh=2g{h}^{\prime }$

$100-2gh=\frac{2gh}{2}$

$3gh=100$

$h=\frac{10}{3}m$

(b)

$0-u^2=-2g\left(\frac{10}{3}\right)$

$u=\sqrt{\frac{200}{3}}$

after 1 sec,

$v=\sqrt{\frac{200}{3}}-\left(10\right)\left(1\right)$

$v=8.16-10=-1.84$$andaccelerationduetogravitywillbealwaysdownward10\frac{m}{s^2}$ m/s2m/s^2