# Initial velocity of the golf ball

1. Dec 14, 2004

### flamegrl

Hey guys
I am kinda new do this forum,
but if any one can help me one this IT would be great
I have this homework problem I tryed many times but can't figure it out,

Tiger Woods can routinely hit a gofl ball 350-yards(320m) assuming he hits at an angle that gives him maxium distance solve the following:
1. initial velocity of the golf ball
2. what is the Maxium height of the golf ball
3. how long does it take to reach the maxium height
4. how ling does it take to travel the 350 yards

2. Dec 14, 2004

### Tjl

Is that all the information given? Because that is an impossible problem unless you make an assumption that no matter the angle, the force exerted on the ball would be the same.

Hint: The maximum distance will be found when both components of the velocity are equal. Think if you hit the ball with force F, at angle 80 degrees, then the x component would be much smaller then the y. So the ball would not travel very far. While if you hit the ball with same force F at angle 30 degrees, with a much higher x component for its velocity, the ball would travel much farther. However the lowest angles will not produce the farthest distance, thanks to gravity.

Last edited: Dec 15, 2004
3. Dec 14, 2004

### flamegrl

Yes that was all the information give!

but I also am having trouble with this one as well
while fishing on a rather hot day you decide, beacuse of the fish aren't biting, to take a break and go to the 7-11 across the river flowing at 4m/s. the river is 500m wide
1. if the boat can travel at 7m/s how long does it take until you reach the other side of the river
2. in what direction relative to the shore must you steer your boat to go straight to the 7-11 the boat is facing north-eat

4. Dec 14, 2004

### Staff: Mentor

You have all the information needed to solve the golf ball problem. Hint: What angle gives the maximum range?

5. Dec 15, 2004

### Tjl

Vectors! Just use vectors for the individuals forces, and make a diagram of them.

$$sin\theta = \frac{Current}{Speed of Boat}$$