Browse Questions

# A man can throw a stone 60 m away . How high can he throw the stone vertically upward?

$\begin{array}{1 1}(A)\;2m \\(B)\;30 m \\(C)\;40 m\\(D)\;25 m \end{array}$

Can you answer this question?

The maximum range given by $R_{max} =\large\frac{v_0^2}{g}$
This shows that the man can throw a stone with a maximum velocity $v_0 = \sqrt { g R_{max}}$.
When he throws the stone vertically upwards with this velocity , the maximum height $H_{max}$ reached is given by
$0= v_0^2 -2gh_{max}$
$H_{max}=\large\frac{v_0^2}{2g} =\frac{gR_{max}}{2g}$
Here $R_{max} =60 \;m$ hence $H_{max} =30 m$
Hence B is the correct answer.
answered Jul 15, 2014 by

+1 vote