I asked about a golf ball hit at a 35 degree angle and the hole was 175 m away. What was speed of ball. I got a response, and it follows with my response. I'm not doing something right, can you help, please.Physics - drwls, Saturday, October 9, 2010 at 10:20am

You can come up with an answer that would cause the ball to reach the hole on the fly, but in most cases you would want to allow for the ball to roll up to the cup, for a shot that long.

To reach the hole as distance X on the fly with an A = 35 degree launch angle, use
X = (V^2/g)*sin(2A) = V^2/g * 0.9397

Plug in X = 175 m and solve for V

Physics-Please check - Anthony, Saturday, October 9, 2010 at 11:23am
I don't think I'm doing this correct.
I took 175 = v^2/9.8 x 0.9397
I did 9.8 x 0.9397 = 9.02
then I took 175/9.20=19.02

This can't be right-did I make a mistake with the variables? I'm not getting this- Please help

YOu didn't do it right.

I took 175 = v^2/9.8 x 0.9397 right
which is 175*9.8/.9397=V^2

First,is that the correct formula? I redid it, I think it should be 43 for the speed. Is that correct? If not, please direct me on what I'm doing wrong.

It is the correct relation. You need to start doing some analysis, not searching for "correct" formulas.

Consider the time in air: vertical
hf=hi+VsinThetat-4.9t^2
VsinTheta=4.9t
t= you do it.
Then,horizontal
distance=VcosTheta*t above, and reduce it.
Remember that sin2A=2sinAcosA

Thank you,

Sorry to have not understood it-I apologize

It appears that you made some errors in your calculations. Let's go through the correct steps to find the speed of the golf ball.

The equation provided by drwls is:
X = (V^2/g) * sin(2A)

Where:
X = Distance to the hole (175 m in this case)
V = Initial velocity of the golf ball
g = Acceleration due to gravity (approximately 9.8 m/s^2)
A = Launch angle (35 degrees in this case)

To solve for V, we need to rearrange the equation and isolate V:

V^2 = X * g / sin(2A)

Now, substitute the given values:
V^2 = 175 * 9.8 / sin(2 * 35)

Next, calculate sin(2 * 35) using a scientific calculator or online calculator, which is equal to 0.5736.

V^2 = 175 * 9.8 / 0.5736

Now, divide both sides of the equation by 0.5736 and take the square root to solve for V:

V = sqrt((175 * 9.8) / 0.5736)

Using a calculator, the approximate value of V comes out to be around 35.4 m/s (meters per second).

So, the speed of the golf ball to reach the hole 175 m away at a launch angle of 35 degrees would be approximately 35.4 m/s.