Final answer:
To calculate the initial velocity with which an object must be thrown vertically upward in order to reach a man on a scaffold 15 ft above, we can use the equation for vertical displacement.
Step-by-step explanation:
To calculate the initial velocity with which an object must be thrown vertically upward in order to reach a man on a scaffold 15 ft above, we can use the equation for vertical displacement:
Δy = V0sinθt −1/2gt2
Where Δy is the displacement, V0 is the initial velocity, θ is the angle of projection (in this case 90 degrees), t is the time of flight, and g is the acceleration due to gravity. In this case, since the object is thrown vertically upward, the displacement Δy is 15 ft.
By rearranging and solving for V0, we can find the initial velocity required:
V0 = Δy / (sinθt − 1/2gt2)
Since the angle of projection is 90 degrees, the sine of 90 degrees is 1.