SOLUTION: Please help!!! Thank you!! Janice tosses a softball directly upward with an intinal velocity of 100 feet per second. Use the formula h=vt-16t^2 to answer each question. a.

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Question 36655This question is from textbook
: Please help!!!
Thank you!!
Janice tosses a softball directly upward with an intinal velocity of 100 feet per second. Use the formula h=vt-16t^2 to answer each question.
a.when will the ball reach the height of 84 feet.
b. when will it hit the ground. This question is from textbook

Answer by venugopalramana(3286) (Show Source):
You can put this solution on YOUR website!
Janice tosses a softball directly upward with an intinal velocity of 100 feet per second. Use the formula h=vt-16t^2 to answer each question.
a.when will the ball reach the height of 84 feet.
H=84=100*T-16T^2....DIVIDING WITH 4
4T^2-25T+21=0
4T^2-4T-21T+21=0
4T(T-1)-21(T-1)=0
(4T-21)(T-1)=0
T-1=0......THAT IS..T=1..IT REACHES 84' FROM GROUND AT T=1 ON UPWARD TRAVEL
4T-21=0....THAT IS..T=21/4..IT REACHES 84' FROM GROUND AT T=5.25 ON DOWNWARD TRAVEL
b. when will it hit the ground.
0=100T-16T^2
4T(4T-25)=0
T=0.....THAT IS BEFORE IT IS THROWN UP
4T-25=0...THAT IS T=25/4=6.25 WHEN IT FALLS BACK ON THE GROUND.