Answer:
70 m/s
Explanation:
The watermelon will go pass superman at the instance when they are at the same distance from the top of the building.
Superman flies by with a constant velocity = 35 m/s
This distance where he will be overtaken by the watermelon will be = vt
where v is his velocity
t is the time the watermelon and superman are side by side
For the watermelon,
the initial velocity u = 0 m/s (since it starts from rest)
The distance where it is side by side with superman will be gotten from the equation
s = ut + [tex]\frac{1}{2}gt^2[/tex]
where is the distance down at which they meet
g is the acceleration due to gravity = 9.81 m/s^2
t is the time they meet
ut = 0, since u = 0 m/s
Equating this distance that they meet, we'll have
vt = [tex]\frac{1}{2}gt^2[/tex]
substituting values, we have
35t = [tex]\frac{1}{2}*9.81*t^2[/tex]
35 = 4.905t
t = 35/4.905 = 7.135 s
The watermelon's speed at this instant can be calculated from
v = u + gt
where v is the velocity at this instant
u = initial speed of the watermelon = 0 m/s
g is the acceleration due to gravity = 9.81 m/s^2
t is the time they meet side by side = 7.135 s
substituting values, we have
v = 0 + 9.81(7.135)
v = 69.99 ≈ 70 m/s
