# Distance golf ball travels

Tags:
1. Jan 2, 2015

### rasen58

1. The problem statement, all variables and given/known data
Golfer hits a golf ball so that it goes with initial velocity of 40 m/s at angle of 45 degrees. 100 m away is a lake that is 50 m wide. The ball will not bounce or roll when it lands. Where does the ball land?
Before, in, or after the lake.

2. Relevant equations
Vertical: a = (v-v0)/t
Horizontal: Δx = v0t+1/2at2

3. The attempt at a solution
I found the time as 2.8 s using the first equation by setting v = 0 (midway in flight), and v0 = 40sin45
Then I substituted the time into the second equation along with 0 for the acceleration since there is no horizontal acceleration and v0 = 40cos45. And got 79 m, so the ball lands before the lake.
But apparently the answer is that it lands after the lake.
What did I do wrong?

2. Jan 2, 2015

### Bystander

This is the time for what?

3. Jan 2, 2015

### rasen58

The time to travel halfway.
Oh... I should've used twice that to get the total time. I get 160 m now.
Thanks, my mistake.

4. Jan 2, 2015

### Bystander

Always try to keep in mind what information you get from a calculation, and what information you've been asked to find.