# How do i find the range?

## Homework Statement

a soccer player kicks a stationary ball at a speed of 20m/s at an angle of 15$$\circ$$ to the horizontal.

## Homework Equations

i think it would be Rmax=Vo2/g ?????

## The Attempt at a Solution

19.32 2/9.8=38.09m ??

I'm really lost can someone help me plz!!

From the angle work out the vertical speed
Then think about how the vertical speed changes with time

hint. what happens at the top of the flight?

mmm... so i calculate the vertical speed: 20sin15=5.18m/s??? and with that i can find at what time it reaches the max height by doing V=Vo+at: V=5,18/9.8= 0.53s do i have to multiply the time by 2 and then do the same thing to find the horizontal range?

X=Xo+Vot-1/2gt(square) where g=0 and Xo=0 too, so it would be X=19.32*(2*0.53s)????

Whats the acceleration in the horizontal direction?

hint. if you ignore air resistance what forces act horizontally

No idea...im sooo lost!!!!! i looked in my book and found this formula R=Vo(square)sin2teta/g omg im freaking out! what Vo i have to take?!? 20m/s? the Vy? or the Vx?

is it (19.32m/s)^2 sin(30)/9.8m/s^2= 19.04m?

hmm...the only force i see is the Vx=20m/s cos 15=19.32m/s it's the only one horizontaly

mmm... so i calculate the vertical speed: 20sin15=5.18m/s??? and with that i can find at what time it reaches the max height by doing V=Vo+at: V=5,18/9.8= 0.53s do i have to multiply the time by 2 and then do the same thing to find the horizontal range?

X=Xo+Vot-1/2gt(square) where g=0 and Xo=0 too, so it would be X=19.32*(2*0.53s)????

All of this is correct!
(Although, you didn't show where or how you got 19.32).

hmm...the only force i see is the Vx=20m/s cos 15=19.32m/s it's the only one horizontaly
Correct, there is no horizontal force, so no aceleration, so speed is constant