SOLUTION: The height {{{highlight(in_feet)}}} of a ball above the ground t seconds after it is thrown is h(t) = 20+32t−16t2. How long will it take for the ball to hit the ground?

Question 1173412: The height of a ball above the ground t seconds after it is thrown is h(t) = 20+32t−16t2. How long will it take for the ball to hit the ground?
Answer by ikleyn(52776) (Show Source): You can put this solution on YOUR website!
.


To answer the problem's question, you need to solve this equation

    -16t^2 + 32t + 20 = 0


and take its larger root.


The equation is equivalent to

    4t^2 - 8t - 5 = 0


Use the quadratic formula

    t =  =  = .


The larger root is   =  = 2.5 seconds.


ANSWER.  The ball will hit the ground in 2.5 seconds.

Solved.

RELATED QUESTIONS
A ball was kicked into the air from a balcony 20 feet above the ground, and the ball's... (answered by vjones93,Alan3354)

A ball was kicked into the air from a balcony 20 feet above the ground, and the ball's... (answered by ikleyn)

A softball is thrown upward. Its path can be modeled by the equation: h(t) = -16t2 + 32t... (answered by ikleyn)

A soccer ball is kicked straight up with an initial velocity of 32 ft. per second. Its... (answered by arallie)

A soccer ball is kicked straight up with an initial velocity of 32 ft. per second. Its... (answered by nerdybill)

Standing on the top of a house 48 feet above the ground, Matt shoots a trick basketball... (answered by Boreal)

A ball is thrown straight up from a rooftop 300 feet high. The formula h = -16t^2 + 20t + (answered by Alan3354)

a tennis ball is thrown into a swimming pool from the top of a hotel. The height of the... (answered by ankor@dixie-net.com)

when a ball is thrown straight up into the air. the formula h=vt-16t2 gives the height h (answered by ewatrrr)