Recent content by moonbase

Okay so it would be 10!/(1!2!3!4!)=12600. Thanks!

Oh okay I put the problem up from memory but I messed up the wording a bit. Anyway, I already know 10! is what it would be if they were all considered different, but I really have no idea where to go from there. Though I did realize this: 10 ncr 1 = 10 10 ncr 2 = 45 10 ncr 3 = 120 10 ncr 4...

EDITED: Should be permutations not combinations Homework Statement You have a bag of 10 marbles. There are 4 red marbles, 3 yellow, 2 green, and 1 blue marble. You remove them from the bag one of the time without replacement. Assuming each color of marble is identical and it doesn't matter...

Nevermind, I realized that the answer is zero. The compression in the center of mass frame is like momentum, the total is zero because the values of both sides cancel out. Thanks for your help though!

Yea I tried that too, the kinetic energy being 11.76 J and the compression being 0.715 m, but that didn't work either. It also didn't accept it when I tried it with what you calculated (0.558 m) so I'm really not sure what's wrong here. If it helps, here's how I got 8.55...

The program doesn't tell me how far off I am, but it told me that 8.55 in indeed correct for the spring's energy. Though when I inquire about it, it says "Look at this in the center of mass frame and consider how there is 8.55 J of mechanical energy. What does this say about the velocity of the...

Homework Statement A cart of mass m = 3 kg carrying a spring of spring constant k = 46 N/m and moving at speed v = 2.8 m/s hits a stationary cart of mass M = 8 kg. Assume all motion is along a line. What is the maximum amount the spring will be compressed? Homework Equations...

Oh okay, I was combining them but I see now. Thank you!

Well I'm trying to figure out where exactly I went wrong. What I did so far: 0.5*20*1.22=14.4 J p2/2(7.5)=14.4 -> p2=216 -> p=14.69 v=p/m -> 14.69/5=2.94 m/s and 14.69/2.5=5.88 m/s Any ideas?

Homework Statement A massless spring of spring constant 20 N/m is placed between two carts on a frictionless surface. Cart 1 has a mass M1 = 5 kg and Cart 2 has a mass M2 = 2.5 kg. The carts are pushed toward one another until the spring is compressed a distance 1.2 m. The carts are then...

Oh, apparently I was right, it was the significant figures that were saying it was wrong. Thanks anyway!

Homework Statement A spring with spring constant k = 50 N/m and unstretched length of L is attached to the ceiling. A block of mass m = 1.5 kg is hung gently on the end of the spring. How far does the spring stretch? Homework Equations PEspring=0.5kx2 Fspring=-kx The Attempt at a Solution...

Ahh I see, I ignored m2's opposing force. Thanks!

Homework Statement Two blocks (m1 and m2) are being pushed to the right along a frictionless table with such a force that the left block (m1), which is smaller, is above the table and not falling. It is pushed up against m2 (which is on the table), and they have a coefficient of static friction...

Oh okay, I was getting static and kinetic friction mixed up. Thanks