An object falls freely from a height of 25m onto the roof of a building 5m high calculate the velocity with which the object strikes the roof
To calculate the velocity with which the object strikes the roof, we can use the basic equations of motion.
We know that the object is falling freely, so its initial velocity is 0 m/s. The height from which it falls is 25m and the height of the roof is 5m.
Using the equation: v^2 = u^2 + 2as
where:
v = final velocity
u = initial velocity
a = acceleration
s = displacement
Here, u = 0 m/s (as the object falls freely), a = acceleration due to gravity (approximately 9.8 m/s^2), and s = 25m - 5m = 20m (as the object falls from a height of 25m to a height of 5m).
Substituting these values into the equation, we get:
v^2 = 0^2 + 2 * 9.8 * 20
v^2 = 0 + 392
v^2 = 392
To find the velocity, we take the square root of both sides:
v = √392
v ≈ 19.8 m/s
Therefore, the velocity with which the object strikes the roof is approximately 19.8 m/s.