A window washer is descending from the top of a skyscraper at a constant velocity of 0.5 m/s. He realizes he forgot his keys and asks his friend to drop them from the roof. He catches them at time t. Which of the following graphs shows the position of the keys as a function of time?

W = 439998 J = 439.99 KJ

Explanation:

First, we will calculate the acceleration of the car by using the first equation of motion:

where,

a = acceleration = ?

vf = final speed = = 30 m/s

vi = initial speed = = 10 m/s

t = time = 30 s

Therefore,

a = 0.67 m/s²

Now, we will calculate the force applied by the engine:

F = ma

where,

F = force = ?

m = mass = 1100 kg

Therefore,

F = (1100 kg)(0.67 m/s²)

F = 733.3 N

Now, we will calculate the distance covered by the car by using the second equation of motion:

s = 600 m

Now, the work done (W) by engine can be calculated as follows:

W = Fs

W = (733.3 N)(600 m)

W = 439998 J = 439.99 KJ