A block of ice starts from rest on an apartment building’s roof, which slopes at 41° below the horizontal. The block slides down the icy frictionless roof for 5.0 m and then leaves the edge, which is 12 m above the ground.
a. How far from the building does the block strike the ground?
b. If a 1.8 m fence stands 6.0 m from the building, show whether or not the ice block will hit the fence.
The Attempt at a Solution
I figured since the ice block starts from rest the initial velocity is 0; the x component of the rooftop vector is 5*cos(-41) = 3.77 and the y component is 5*sin(-41) = -3.28. I struggle with finding a way to find the final velocity when the ice block leaves the rooftop. My goal was to use the point where the block leaves the rooftop as origin and the 12m as my negative y-axis to calculate the trajectory which will answer part a and b. Can I use r_f = r_i + v_i * t + 1/2 * g * t^2 to get the time? I solved for t and got t = 5m + 1/2(-9.8) = 9.9s but I am not sure if this is right. I would appreciate your support.