Recent content by Cfem

Homework Statement You have several identical balloons. You experimentally determine that a balloon will break if its volume exceeds 0.900L . The pressure of the gas inside the balloon equals air pressure (1.00 atm). The air inside the balloon has a constant temperature of 22 C. How many...

This isn't a HW question exactly, but I'm trying to model planetary motion and I've having trouble remembering something I learned a while ago when I took physics. I remember that the tangential velocity for a something to orbit a planet is v = sqrt(-G * M/r), but I need to decompose this...

I hadn't thought about the energy perspective. Thanks for that one. But about finding the max acceleration... Since the potential of a spring is given by (1/2)(k)(x^2), I figure it was intuitive that the max acceleration would be when the spring is stretch to its max distance, its...

Homework Statement A 130 g ball attached to a spring with spring constant 3.0 N/m oscillates horizontally on a frictionless table. Its velocity is 17 cm/s when x = 4.2 cm Find the: -Amplitude of Oscillation -Max acceleration -Speed of the ball when x = 2.8cm Homework Equations T =...

Ugh. Ia = (1/12)(2.5)(.12) + 2.5(.432) Plugging in the new values gives me a final rotational speed of .98 rev/s, which is slower. I hate rotational motion.

Okay, I get that I should use the parallel-axis theorem, but I'm a little confused about how to apply it. Would it be the moment of inertia as I calculated it + the mass of the rod times the radius of the skater's torso? The definition says that you should take the moment of inertia about...

Homework Statement A 45 kg figure skater is spinning on the toes of her skates at 1.0 rev/s. Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg, 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each...

That might have been one of those "two o'clock in the morning typos". That should say (1/3)(mR)(L2) + that second half. Formula of a rod rotated about an end summed with the moment of inertia of the bullet and block, treated as a point. Beyond that, is there any other mistakes? Thanks for...

I only have one more attempt on this question before I lost all of the points, so detailed help would be much appreciated. I understand everything conceptually (I think), but I don't know where I went wrong. Homework Statement A 2.3 kg wood block hangs from the bottom of a 1.3 kg, 1.3 meter...

h would have been L - Lcos35 if it were massless. That's my slip up. But back to the question at hand, though, I'm lost now. Would I have to use the center of mass of the pendulum and the block? That sounds complicated. Is there another way I could do it?

Homework Statement A 2.3 kg wood block hangs from the bottom of a 1.3 kg, 1.3 m long rod. The block and rod form a pendulum that swings on a frictionless pivot at the top end of the rod. A 12 g bullet is fired into the block, where it sticks, causing the pendulum to swing out to a 35 degrees...

Me too ._. So I think I've nailed down most of what I missed. the normal force on the right pivot would be the weight of the boy + the weight of the beam, yes? Gravitational torque is just the term our textbook uses for the torque acting on the center of mass. Put all in all, the...

i] Okay. I understand that one. Due to not paying attention ._. ii] This one I'm not sure about. Did you mean I should take the weight of the beam into account when calculating the Normal force or when I'm calculating the torque> iii] I hate rotational motion. Didn't even occur to me. So then...

Homework Statement A 45 kg, 5.0 m-long beam is supported, but not attached to, the two posts in the figure . A 25 kg boy starts walking along the beam. How far can he get to the end without falling over? Homework Equations Support on the left is leftEnd, support on the right is...

So then the force acting up the hypotenuse is 200N times the sine of the angle? Sorry for all the questions. I can't get the picture right geometrically. On paper or in my head.