- #1
moonpearl
- 9
- 0
hi there, I'm planning to take university physics in the fall, but I'm lousy at it and doing some practise problems in advance :( i was doing some loop problems, and I'm extremely confused and disheartened and was wondering if anyone could help me?
The set up is pretty simple:
- there is a ramp of height, H
- A block is released from H
- At the bottom of the ramp there is a loop with radius of 10m, and R<H
- The block is 1kg
The question I got stuck on is:
1. How fast does the block need to be going at the bottom of the ramp so that the acceleration of the block at the top of the loop is 4g?
- I thought this was simply A=v^2/r, where A=4g, giving me v=(4gr)^(1/2).
- I put in R=10, my answer is wrong, and I guess it wasn't as simple I thought. :| How should I actually go about this?
I also don't get this question:
2. What is the speed of the block as it exits the loop if the normal force at the top of the loop was 80N.
-I made Fnet=normal force + mg, then substituted to get Fnet=80+(1kg)(9.8N)=898N.
- Made Fnet=(mv^2)/r, where r=10. Again, my answer is wrong, so am I just oversimplifying these problems? Is there a better way to do them?
Thanks so much in advance!
Lori-Anne
The set up is pretty simple:
- there is a ramp of height, H
- A block is released from H
- At the bottom of the ramp there is a loop with radius of 10m, and R<H
- The block is 1kg
The question I got stuck on is:
1. How fast does the block need to be going at the bottom of the ramp so that the acceleration of the block at the top of the loop is 4g?
- I thought this was simply A=v^2/r, where A=4g, giving me v=(4gr)^(1/2).
- I put in R=10, my answer is wrong, and I guess it wasn't as simple I thought. :| How should I actually go about this?
I also don't get this question:
2. What is the speed of the block as it exits the loop if the normal force at the top of the loop was 80N.
-I made Fnet=normal force + mg, then substituted to get Fnet=80+(1kg)(9.8N)=898N.
- Made Fnet=(mv^2)/r, where r=10. Again, my answer is wrong, so am I just oversimplifying these problems? Is there a better way to do them?
Thanks so much in advance!
Lori-Anne