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

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

Step-by-step 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+(1)/(2)gt^2`

Here u = 0

`d=(1)/(2)gt^2`

`39t=(1)/(2)* 9.8* t^2`

t = 7.95 seconds

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

`v=gt`

`v=9.8* 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.