Sunday

November 23, 2014

November 23, 2014

Posted by **rmj** on Saturday, February 14, 2009 at 9:10pm.

# A soccer ball is kicked from the ground. When it reaches a height of 5.93 m, the velocity is v=6.45i+7.46j m/s.

1. Determine the maximum height that the ball reaches. (the right answer is 8.77 m)

2. Determine the total horizontal distance travelled by the ball.

3. What is the speed of the soccer ball just before it hits the ground?

for number 2, i found the total time from yf = yi + viyt - 1/2gt^2

and plugged it into vx=dx/t to get the horiz distance but i still can't

get the right answer

did i miss anything?

- physics -
**drwls**, Saturday, February 14, 2009 at 10:47pmThe time the ball is in air is

2*Vyo/g , where Vyo is the initial vertical velocity component. Solve for that first.

From energy considerations,

7.46^2/2 + gH = Voy^2/2

Voy^2/2 = 86.0 m^2/s^2

Voy = 13.11 m/s

so T = 2.67 s

The distance travelled in that time is

Vx*T = 17.24 m

- physics -
**Ross**, Monday, April 12, 2010 at 1:55pmThe way I solved the first part of the question was:

Vo=?

d=7.18 m

Vf = 7.80m/s

a = 9.81m/s^2

So find the initial Vo velocity using:

Vf^2 - Vo^2 = 2ad

Then once you get Vo, use the same equation to find the d, when Vf = 0, that's when the height is maximal.

Hope that helps.

Cheers,

Ross

- physics -
**emg**, Saturday, May 15, 2010 at 9:25pmdrwls - could you please explain the reasoning behind this:

"From energy considerations,

7.46^2/2 + gH = Voy^2/2

Voy^2/2 = 86.0 m^2/s^2

Voy = 13.11 m/s

so T = 2.67 s

What does "H" represent? Why can't you just use the total time that the ball is in the air, and multiply that by the initial x-component of velocity? Since d=vt

- physics -
**Anonymous**, Saturday, February 5, 2011 at 3:45pmthe G represents gravity, and H represents the height

**Answer this Question**

**Related Questions**

math - The height of a soccer ball that is kicked from the ground can be ...

algebra 1 NEED NOW!!! PLEASE HELPPP - The height of a soccer ball that is kicked...

algebra 1 NEED NOW!!! PLEASE HELPPP - The height of a soccer ball that is kicked...

physics - A soccer ball is kicked off of the ground at 17 ft/sec @ 30 degrees. ...

Physics - 2-D kinematics - A soccer ball is kicked with an initial horizontal ...

math - A soccer ball is kicked upward from the ground and its height (in metres...

Physics - A soccer ball is kicked with an initial horizonal velocity of 18 m/s ...

Physics - A soccer ball is kicked off a bridge with a height of 36 m. The ball ...

math - When a soccer ball is kicked with a vertical speed of 25 m/s its height, ...

college - Q. A soccer ball is kicked from the ground. When it reaches a height ...