Question

A stone is thrown vertically upward with an initial velocity of 40 m/s. Find the maximum height reached by the stone. (Take $g=10m{s}^{-2}$)

• A. 40 m
• B. 80 m
• C. 160 m
• D. 200 m

Answer 1

The correct option is C 160 m

Given, a stone is thrown vertically upwards.
Initial velocity, u = 40 m/s
Acceleration due to gravity, $g=-10m{s}^{-2}$
When the stone reaches a maximum height, v = 0
Now, using the third equation of motion,
$v^2$ - $u^2$ = 2gs
We have,
$0^2$ - ${40}^2$ = 2 $\times$ (-10) $\times$ s
s = $\frac{40\times 40}{20}$ = 80 m
Total distance covered = 80 m + 80 m = 160 m