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## Homework Statement

A ball is thrown vertically downward with a velocity of 30 ft from the top of a building.

Find

a.)What it's speed will be after falling 2 seconds

b.)How far it will fall in 2 seconds

c.)What will be its velocity after 30 ft

d.)If the ball was released at 120 ft above the ground, in how many seconds will it strike the ground.

## Homework Equations

For a I used the equation Vy = Vyo - gt

For b I used the equation ΔY=Vyo(t) - 1/2gt^2

For c I used the equation ΔY=Vyo(t) - 1/2gt^2 in order to find t, or the time it takes to move 30 ft and I got .72 s. Then I put that into the first equation of Vy=Vyo - gt.

For d I used ΔY=Vyo(t) - 1/2gt^2.

## The Attempt at a Solution

For a I got -94 ft/s.

For b I got -124 ft/s.

For c I got 53.04 ft/s.

For d I got 2.74 seconds

I have a few questions. First, can someone check if these answers are correct? My professor did not provide an answer sheet for the exam review. Also I was only able to get a proper answer for d if I made the 120 ft negative. If the ball was released at 120 ft above the ground wouldn't it be positive? Also, c gave me some trouble, if it is incorrect, could someone please provide an in-depth explanation? Thank you so much.