SOLUTION: Suppose someone threw a stone off a 100 m cliff. The height of the stone, h(t), in metres, after t seconds can be represented by the function {{{ -4.9t^2+3t+100=h(t) }}}. How long

Question 940148: Suppose someone threw a stone off a 100 m cliff. The height of the stone, h(t), in metres, after t seconds can be represented by the function . How long would it take for the stone to hit the ground?
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!
.
(tossing out negative solution for unit measure)
t = 4.83402198619057 sec

Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=1969 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: -4.22177708823139, 4.83402198619057. Here's your graph:

RELATED QUESTIONS
A stone is dropped off a 256 ft cliff. The height of the stone above the ground is given... (answered by josgarithmetic)

A stone is thrown upwards with an initial speed of 56 m/s. its height is h metres above... (answered by josmiceli)

A stone was thrown from the top of a cliff 60 meters above sea level. The height of the... (answered by Alan3354)

Please help me solve this problem A person on the edge of a cliff throws a stone so that (answered by ankor@dixie-net.com)

A stone is thrown vertically upward from the roof of a building. The formula that... (answered by Alan3354)

Can someone check my work please? I hope I'm not missing any steps and that I'm on the... (answered by jim_thompson5910)

A stone is thrown vertically upward from the roof of a building. The formula that... (answered by Alan3354)

. Tobey sits by the lake and throws a stone into it. The path of the stone is described... (answered by ikleyn)

Ushna sits by the lake and throws a stone by it. The path of the stone is described by... (answered by ewatrrr)