Question

a stone is vertically thrown upward with the velocity of 72km/hr find the maximum height reached the height​

Answer 1

Answer:

y = 20.38 [m]

Explanation:

In order to solve these problems, we must use the following kinematics equation.

$v_{f} ^{2} =v_{i} ^{2}-(2*g*y)$

where:

Vf = final velocity = 0

Vi = initial velocity = 72 [km/h]

g = gravity acceleration = 9.81 [m/s^2]

y = vertical elevation [m]

We need to convert [km/h] to [m/s]

$72[\frac{km}{h}]*[\frac{1h}{3600s}]*[\frac{1000m}{1km} ] = 20 [m/s]$

Note: the negative sign of the equation means that the acceleration acts in the opposite direction to the movement of the body. And the final speed is zero, because when the body reaches the maximum height, the Stone does not move its speed has been reduced to its entirety.

0 = (20)^2 - (2*9.81*y)

20^2 = 2*9.81*y

y = 20.38 [m]