Question

The cup on the 9th hole of a golf course is located dead center in the middle of a circular green that is 70 ft in diameter. You ball is located 50 feet south, and 40 feet west of the cup. The ball follows a straight line path and exits the green at the right most edge. Assume the ball travels a constant rate of 10ft/sec.

a. Where does the ball enter the green?

b. When does the ball enter the green?

c. How long does the ball spend inside the green?

d. Where is the ball located when it is closest to the up and when does this occur?

Answer 1

Assuming the "rightmost edge" of a circle is the end of the horizontal diameter, we have

hole is at H:(0,0)
ball is at B:(-40,-50)
ball exits at P:(35,0)

So, the line joining B and P is
y+50 = 2/3 (x+40)

The circle is represented by
x^2+y^2 = 35^2

The line intersects the circle at
Q:(-13,-32) and P:(35,0)


BQ = 32.5
So, assuming the ball is hit at time t, it reaches Q at t = 3.25

Now you can figure PQ and the time spent on the green.

Answer 2

Thank you!!! I understand how to do these kinds of problems again. Though I spent nearly 2 hours doing this, it feels all worth it to understand how to actually do it. :) Thank you once again!!!!!!

Answer 3

How would you do d)?