# Modeling motion using parametirc equations?

• Apr 2nd 2011, 10:33 AM
homeylova223
Modeling motion using parametirc equations?
1. Professional golfer Lopez hits a golf ball with a force to produce an initial velocity of 175 feet per second at an angle of 35 above the horizontal. She estimates the distance to the hole to be 225 yards.

So I made my parametric equations

x= T 175cos(35)
y= T 175sin(35)-16t^2

Find the range of the ball? How would I find the range of the ball?

2. Alfredo is performing a physics experiment in which he will launch a rocket the rocket is supposed to release a parachute 300 feet in the air 7 seconds after liftoff. He is firing the rocket at 78 degrees from the horizontal.

I know the initial velocity is 158.31 ft/s using my parametric equation

Now it ask me "to protect other students from falling rocket the teacher need to place warning sings 50 yards from where the parachute is released. How far should the sings be from the point where the rockets are launched"?

How would I figure this out.

Can anyone show me how to these two problems
• Apr 2nd 2011, 10:57 AM
skeeter
Quote:

Originally Posted by homeylova223
1. Professional golfer Lopez hits a golf ball with a force to produce an initial velocity of 175 feet per second at an angle of 35 above the horizontal. She estimates the distance to the hole to be 225 yards.

So I made my parametric equations

x= T 175cos(35)
y= T 175sin(35)-16t^2

Find the range of the ball? How would I find the range of the ball?

set y = 0 , solve for the non-zero value of t ... sub that value of t in for x to find the range

2. Alfredo is performing a physics experiment in which he will launch a rocket the rocket is supposed to release a parachute 300 feet in the air 7 seconds after liftoff. He is firing the rocket at 78 degrees from the horizontal.

I know the initial velocity is 158.31 ft/s using my parametric equation

Now it ask me "to protect other students from falling rocket the teacher need to place warning sings 50 yards from where the parachute is released. How far should the sings be from the point where the rockets are launched"?

the rocket will be a horizontal distance x = 158.32cos(78)*7 from the launch position when the chute opens

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