Question

As a science project, you drop a watermelon off the top of the Empire State Building, 320 m above the sidewalk. It so happens that Superman flies by at the instant you release the watermelon. Superman is headed straight down with a speed of 39.0 m/s.
How fast is the watermelon going when it passes Superman?

Answer 1

Answer:

The velocity of watermelon when it passes Superman is 78 m/s.

Explanation:

Height of the building, d = 320 m

Speed of the superman, v = 39 m/s

We need to find the speed of watermelon when it passes Superman. Let t is the time taken by the watermelon. So,

$d=ut+\dfrac{1}{2}gt^2$

Here u = 0

$d=\dfrac{1}{2}gt^2$

$39t=\dfrac{1}{2}\times 9.8\times t^2$

t = 7.95 seconds

Let v is the speed of the watermelon. It is given by :

$v=gt$

$v=9.8\times 7.95$

v = 77.91 m/s

or

v = 78 m/s

So, the velocity of watermelon when it passes Superman is 78 m/s.