t = 5.05 sec
Solution:
Given data:
Initial height = 24 meter
Initial velocity = 22 meter
Height of the rock (h) = 10 meter
To find when will the height of the rock be 10 metres:
General formula for the height(meter) of a projectile over time:
Substitute the given data in the above formula.
This equation looks like a quadratic equation.
We can solve it by using the quadratic formula:
Here a = –4.9, b = 22, c = 14
Time cannot be indicated in negative. So neglect t = –0.56.
Therefore, t = 5.05 sec
Hence after 5.05 sec the rock will be 10 meters from ground level.