Posted by **NeedHelp** on Saturday, February 12, 2011 at 11:57pm.

A cannon shell is fired up in the air at an initial speed of 225m/s.

After how much timeis the shell at a height of 6.20 X 102 and heading down. What equation would be used to solve this?

- physics -
**Henry**, Monday, February 14, 2011 at 1:49am
Vf^2 = Vo^2 + 2(-9.8)d = 0,

(225)^2 - 19.6d = 0,

50625 - 19.6d = 0,

-19.6d = -50625,

d(up) = 2583m, max.

d = Vot + 0.5gt^2 = 2583 - 620 = 1963m

225t + 4.9t^2 = 1963,

4.9t^2 + 225t -1963 = 0,

Solve using Quadratic Formula and get:

t = 7.49958s, and t = - 48.526.

Use positive value of t.

t(down) = 7.49958s = time to go from

2583m to 620m.

## Answer this Question

## Related Questions

- science - a shell is fired from the cannon. the shell of mass 30kg is shot with ...
- physics - A cannon fires a shell at an angle of 55.0° above the horizontal. The...
- physic - 3) A shell is fired from ground level with a muzzle speed of 350 ft / s...
- calculus - 3) A shell is fired from ground level with a muzzle speed of 350 ft...
- Physics - A cannon fires a shell at an angle of 55.0 above the horizontal. The ...
- physics - A shell fired from the ground with an initial speed of 1.70 x 10^3 m/...
- physics - A shell is fired from the ground with an initial speed of 1.54 103 m/s...
- physics - A shell is fired from the ground with an initial speed of 1.58 103 m/s...
- Physics - A shell is fired from the ground with an initial speed of 1.68 103 m/s...
- Physics - A shell is fired from the ground with an initial speed of 1.54 ✕...