Mr. D s dog Gromit jumped out of a second story window (through the screen) and

Vf = 9.46 m/s

Explanation:

In order to find the final velocity of the dog we can use third equation of motion:

2gh = Vf² - Vi²

where,

g = acceleration due to gravity = 9.8 m/s²

h = height of window = (15 ft)(1 m/3.28 ft) = 4.57 m

Vf = Final Velocity of Dog = ?

Vi = Initial Velocity of Dog = 0 m/s

Therefore,

(2)(9.8 m/s²)(4.57 m) = Vf² - (0 m/s)²

Vf = √(89.572 m²/s²)

Vf = 9.46 m/s

The forces are equal in size and opposite directions so they are balanced, zero net force