Need some help on simple question 14 replies

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Guest

I didn't make it!

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#1 10 years ago

I'm not in this kinda math yet. Lol. I need help on this problem. I can't say what it's for BUT IT IS NOT FOR SCHOOL OR ANYTHING THAT WOULD HELP ME CHEAT IN LIFE! Just a little contest on another site.

Problem: In 2035 man built the first frictionless roller coaster on the moon (g=1.6m/s^2) called the Rocket. It started at ground level and was transported up a straight inclined plane at a speed of 18 km/h by a 40 watt motor using 1200J to pull the coaster car to the top. From the bottom to the top of the inclined plane the coaster car is displaced 30m [E]. At the top of the incline the 2000kg coaster comes to a stop before being dropped down a hill. The coaster car then comes to the bottom of the hill at ground level. It then goes around a loop reaching 54 km/h at the top of the loop. Find the maximum height of the loop.

216,579 XP

7th December 2003

19,982 Posts

#2 10 years ago

You expect me to win a contest and leave the fame to you? I don't think so.

But I'll give you a few tips that might work: calculate potential energy at h (with all the information like speed, energy used and distance you should be able to calculate how much potential energy the car gained), then convert the potential energy to kinetic energy for the point at the end of the slope. Now convert it back to potential energy (to find out height of loop) but keep in mind that the centrifugal force in the loop (proportional to speed and the height/2) has to equal gravity at point b so that the car doesn't fall down.

Jeff is a mean boss

564,280 XP

28th July 2002

53,056 Posts

#3 10 years ago

Personally I'd just make something up and hope for the best

Speer

GF's Cheerios Expert

50 XP

16th January 2008

2,082 Posts

#4 10 years ago

I'll work it out when I'm done doing my homework... In other words, tonight... 'Tis actually what I'm working on, my homework is similar to this...

Guest

I didn't make it!

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#5 10 years ago

Heh. Alright. I see what you Mr. Fancy Pants. I'll try to figure it out. I'm not that far into math yet. I'll see what I can do myself. And thanks Speer. I'll see what I can do myself as well though.

Junk angel

Huh, sound?

166,880 XP

28th January 2007

15,678 Posts

#6 10 years ago

just change g in most equations for the same amount what's on the moon.

Speer

GF's Cheerios Expert

50 XP

16th January 2008

2,082 Posts

#7 10 years ago

Crap, now that I look over it more it's physics not math... I'm still in High School, so I don't really get it... But I'll try some more nevertheless, sorry I didn't get it.

colonel_bob

Here & There

50 XP

4th June 2004

6,685 Posts

#8 10 years ago
MrFancypants;4304775You expect me to win a contest and leave the fame to you? I don't think so. But I'll give you a few tips that might work: calculate potential energy at h (with all the information like speed, energy used and distance you should be able to calculate how much potential energy the car gained), then convert the potential energy to kinetic energy for the point at the end of the slope. Now convert it back to potential energy (to find out height of loop) but keep in mind that the centrifugal force in the loop (proportional to speed and the height/2) has to equal gravity at point b so that the car doesn't fall down.

This. Alot of physics problems can be really simplified if you reduce them to kinetic/potential energy. Basically, find the total kinetic and potential energy of the car at the top of the slope, and subtract the kinetic energy of the coaster going 54 km/h from that value. That gives you the total potential energy of the car at the top of the loop, from which its pretty easy to find the height of the loop. Plugging in the equations should take, I dunno, about 5 minutes?

Guest

I didn't make it!

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#9 10 years ago

b < h

i would have a go at this but i am to lazy to convert km/h into ms as that is the standard unit but it aint that hard and what people have said above it all true

Nature's best screw up.

132,255 XP

26th July 2005

12,663 Posts

#10 10 years ago
S.T.A.L.K.E.R.;4304782Personally I'd just make something up and hope for the best

33 Meters high.

...times Pi

All divided by August 14.

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