How far away will the ball land?

Homework Statement

A ball rolls off an incline at a velocity of 22m/s. The angle of the incline is 32deg, and the height of the incline from the floor is 9m. Assume no air resistance.

d=vit+1/2at^2

The Attempt at a Solution

I figured i should attempt to separate the motion of the ball into the x and y dimensions first so this was my attempt:
y motion
---------
22sin32*=11.7m/s
d=9m
vf=17.7m/s
a=-9.8
t=0.74

x motion
----------
vi=vf=18.7m/s because 22cos32=18.7m/s
t=0.74s

Doc Al
Mentor
y motion
---------
22sin32*=11.7m/s
d=9m
vf=17.7m/s
a=-9.8
t=0.74
How did you solve for the time?

time
-----
9=11.7t+1/2(-9.8)t^2
9=11.7t - 4.9t^2
-2.7/-4.9=.55
sqrt .55=.74s

Doc Al
Mentor
time
-----
9=11.7t+1/2(-9.8)t^2
Careful: Check the sign of your 'd' and 'vi'.

oops...I guess 'd' is -9 because it is pointing down? And 'vi' is -11.7 because of direction too?
I got a new time of .64s
If the above is correct, i still don't know how to solve this problem...help please? Thank you.

Doc Al
Mentor
oops...I guess 'd' is -9 because it is pointing down? And 'vi' is -11.7 because of direction too?
Yes.
I got a new time of .64s
My answer is close to that.
If the above is correct, i still don't know how to solve this problem...help please?
Now consider the horizontal motion. You have the speed and the time.

d=vt
So, d= (18.7)0.64
= 11.9m
Is that correct for distance?

Doc Al
Mentor
d=vt
So, d= (18.7)0.64
= 11.9m
Is that correct for distance?
That's the correct method. My answer is a bit less; try doing the calculation with more accuracy until the end.

Yes okay thank you, because it looks like the answer in the book is around 0.9 metres less than my value. How do i calculate with more accuracy throughout in the future please?

Doc Al
Mentor
How do i calculate with more accuracy throughout in the future please?
Just carry all intermediate values with more digits. Round off only at the end. For example, instead of 22sin32 = 11.7, use 11.66. And so on.

Just carry all intermediate values with more digits. Round off only at the end. For example, instead of 22sin32 = 11.7, use 11.66. And so on.

Thank you for all your help! I can see where my answers have been off marginally on previous problems due to rounding off the intermediate values too soon as it were. 