11. A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It
strikes the ground after 2.0 s. How high is the building, assuming negligible air resistance?
(Use g = 10 m/s²)
To solve this problem, we can use the equation for the height of an object in free fall:
h = v0t + (1/2)gt^2
where h is the height, v0 is the initial velocity, t is the time, and g is the acceleration due to gravity.
Given:
v0 = 25 m/s
t = 2.0 s
g = 10 m/s²
We can substitute these values into the equation:
h = (25 m/s)(2.0 s) + (1/2)(10 m/s²)(2.0 s)^2
h = 50 m + (1/2)(10 m/s²)(4.0 s²)
h = 50 m + 20 m
h = 70 m
Therefore, the height of the building is 70 meters.