Monday

October 20, 2014

October 20, 2014

Posted by **Brynn** on Sunday, September 23, 2012 at 10:51pm.

What is the height of the rock after 3 seconds?

How long will it take the rock to hit the bottom?

- algebra -
**Reiny**, Sunday, September 23, 2012 at 11:18pmYour equation should read

h(t) = -9.8t^2 + 100

when t = 3

h(3) = -9.8(9) + 100

= 11.8

it will be 11.8 m above the ground

how long to hit ground ??

when h(t) = 0

0 = -9.8t^2 + 100

9.8t^2 = 100

t^2 = 100/9.8 = 10.204..

t = √10.204.. = appr 3.2 seconds

**Answer this Question**

**Related Questions**

Pre-Algebra - You drop a rock off a bridge. The rock's height, h(in feet above ...

physics - A rock is dropped off of a bridge into the water below. If the ...

algebra 1 - The formula for the height of a falling object is shown below, where...

Calculus - Here is my problem that I am trying to work on: A rock is dropped ...

pre-cal - aj uses a lingshot to launch a rock straight up from the a point of 6...

math - The height, in feet, of a free]falling object t seconds after being ...

math - The height, in feet, of a free-falling object t seconds after being ...

math - the height, in feet, of a free-falling object t seconds after being ...

Calculus - well i have this homework question that says: A rock is dropped from ...

Polynomials - A rock is thrown upward at a speed of 10 metres per second. The ...