Recent content by asdf12321asdf

Ok, will do. Thanks again for the help!

It was right! Thanks so much. I'm a bit confused by the answer though. Does 1K = 1C because of the fact that a change in 1 degree in both K and C is the same amount? Also, how am I supposed to know that they want 1K = 1C rather than 1K = -272.15?

Homework Statement I feel stupid posting this but I am completely lost. This is a problem on my Chemistry textbook's website, which gives immediate feedback on whether you are right or wrong, and I am just unable to get it right. The question: What is the difference between a kelvin and a...

oh ok I figured it out thanks a lot

Homework Statement A stationary observer at a crosswalk hears an ambulance siren with an apparent frequency of 480 Hz when the ambulance is approaching. After the ambulance passes the apparent frequency is only 420 Hz. Find the speed of the ambulance. Assume v = 343 m/s for the speed of sound...

Oh ok I actually see that equation in my notes, except it is marked as the parallel axis theorem, but I see that they are the same thing. Well I used the equation to find 'I' for the edge of the disk and then used L = Iω and got the right answer! Thanks a lot for all the help, it really...

Ok thanks, I didn't realize L = r x p was only for that. I instead tried it with L = Iω and got .984 which is the correct answer. For part (b), I don't think we ever learned about Steiner's theorem. I don't see it in my notes and it is not in the index of my textbook. Maybe I'm just missing...

Homework Statement A uniform solid disk of mass m = 4.50 kg and radius R = 25.0 cm rotates at 7.00 rad/s about an axis perpendicular to the face of the disk. Calculate the magnitude of the angular momentum of the disk (a) when the axis of rotation passes through the center of the disk, and...

Thanks a lot! I changed the weights and then added the two equations and solved for vf and ended up with the correct answer. I was pretty clueless as to how to solve this question initially, but now I think I am starting to get it. Thanks again!

Ok I got that Yf of mass2 is 2. And if I write the equation for each mass I get: mass1 (.5)(18)(vf)² + (18)(9.8)(0) = (.5)(18)(0) + (18)(9.8)(4) mass2 (.5)(18)(vf)² + (18)(9.8)(2) = (.5)(18)(0) + (18)(9.8)(0) Is that right? Does that help me at all?

Homework Statement Two masses are connected by a light string running over a frictionless pulley as shown below. The system is initially at rest and the incline is frictionless. If m1 = 10.0 kg, m2 = 8.00 kg and the incline makes a 30o angle from the horizontal, use energy methods to find the...

Oh wow, thanks a lot. I changed the m in Uf to .15 and then got 16.6m which is the correct answer. It's unfortunate I've spent all this time on this problem due to this small error, though it's reassuring to know I was doing it the right way at least. Thanks again!

Homework Statement 3. A baseball (m = 0.150 kg) is thrown with an initial speed of 30.0 m/s at an angle of 37.0 degrees from the horizontal at y = 0 m. (a) Find the initial KE of the ball. (b) Use conservation of energy (not kinematic equations) to find the maximum height reached by the ball...

Thanks for the help! I realized I had to also add the normal force when it was at part a. I was able to figure out part b and c based on that information.

Homework Statement The roller coaster car shown below has a mass of 800 kg when fully loaded with passengers. (a) If the car has a speed of 25.0 m/s at point A, what force does the track exert on the car at that point. (b) If the car has a speed of 10.0 m/s at point B, what force does the track...