SOLUTION: A ball is thrown upward with an initial velocity of 80 feet per second from the edge of a cliff that is 384 feet above a river. Use the function
a) How long will it take for t
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a) How long will it take for t
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Question 1030331: A ball is thrown upward with an initial velocity of 80 feet per second from the edge of a cliff that is 384 feet above a river. Use the function
a) How long will it take for the ball to land in the river?
You can put this solution on YOUR website! A ball is thrown upward with an initial velocity of 80 feet per second from the edge of a cliff that is 384 feet above a river.
Use the function: h(t) = -16t^2 + 80t + 384
:
a) How long will it take for the ball to land in the river?
The river is h(t) = 0
-16t^2 + 80t + 384 = 0
Simplify, divide equation by -16
t^2 - 5t - 24 = 0
Factors to
(t-8)(t+3) = 0
positive solution
t = 8 seconds to land in the river
;
b) When is the ball 480 feet above the river?
h(t) = 480
-16t^2 + 80t + 384 = 480
-16t^2 + 80t + 384 - 480 = 0
-16t^2 + 80t - 96 = 0
Simplify, divide by -16
t^2 - 5t + 6 = 0
Factors to
(t-3)(t-2) = 0
At 480 ft twice
t = 2 sec on the way up
and
t = 3 sec on the way down
