# Marble Roller Coaster Help

1. Nov 22, 2004

### ameriland_06

In my 11th grade physics class we had to design and make a marble roller coaster. Now we have to write a paper explaining how one aspect of our coaster works. I chose to do the jump, but I really have no idea how to explain how this works using physics. Can someone please help me? Also you can add me and talk to me on msn, Ameriland_06@hotmail.com

2. Nov 22, 2004

### ameriland_06

Someone please help me?? i really need help.... if you could just put me on the right track. I'm as lost as a snow goose in a blizzard..

3. Nov 22, 2004

### ameriland_06

Please someone.... My time is running out... i need help

4. Nov 22, 2004

### BobG

Compare the vertical components of the marble's velocity with the horizontal.

The marble is traveling a certain speed and the jump is probably angled upward by some angle. The marble's vertical velocity is it's speed times the sine of the angle of the jump. The horizontal velocity is the marble's speed times the cosine of the angle of the jump.

Look up the equation for motion in your physics book. The vertical component is affected by gravity. The horizontal component isn't.

5. Nov 22, 2004

### ameriland_06

Thanks for the help, your a really awesome guy for doing this....

6. Nov 22, 2004

### ameriland_06

umm.... i am having a problem with your with your explination of how a jump works in my marble roller coaster. "The marble is traveling at a certain speed and the jump is angled upward by some angle. The marble's vertical velocity is its speed times the sine of the angle of the jump. The horizontal velocity is the marble's speed times the cosine of the angle of the jump." How does the horizontal and vertical velocity explain why it jumps and works? would it be that the vertical velocity overcomes gravity and the horizontal allows it to continue going forward? Please and Thank you...

7. Nov 22, 2004

### BobG

Well, it has enough of an initial velocity to overcome gravity for a while. But gravity is accelerating the marble downward. Did you look up your equation for motion. Initial position is posivite (the end of the ramp is above the ground) and the initial velocity is positive (up). Acceleration is negative, since gravity is pulling down.

Horizontal motion is perpendicular to the pull of gravity, so gravity has no affect on the horizontal motion.