# Recent content by CaptainSFS

1. ### Linear and Rotational Kinematics System.

Alright Block 1: T1 - Frictional Force = m*a Block 3: m3*g - T3 = m*a Pulley 2: (1/2)m2*r*a = (T3 - T1)*r Then, T1 = m1*a + m1*g*u | T3 = m3*g - m3*a <--I plug these two into my 'Pulley 2' I then algebraically solve for a and I end up with, a = (m3*g - m1*g*u) / (0.5*m2 + m1 + m3) I...
2. ### Linear and Rotational Kinematics System.

torque has units of Nm. So I need some sort of distance I take it? Would I use the radius as this distance? Would it be Torque=(T3-T1)r ? EDIT: This also doesn't seem to work. I'm feeling pretty lost at this point. =/
3. ### Linear and Rotational Kinematics System.

Homework Statement A block of mass m1 = 2 kg rests on a table with which it has a coefficient of friction µ = 0.53. A string attached to the block passes over a pulley to a block of mass m3 = 4 kg. The pulley is a uniform disk of mass m2 = 0.4 kg and radius 15 cm. As the mass m3 falls, the...
4. ### Rotational Kinematics - Cylinder down a slope.

I also tried using the gravitational force as the Torque. I used m*g*sin(20)=I*alpha m*g*sin(20)/I=alpha and alpha*R = a so... m*g*sin(20)*R/I=a, but this didn't work either. ------------------- I just solved this problem.
5. ### Rotational Kinematics - Cylinder down a slope.

Are they the same? b/c the frictional force is a force not coming out from the CM; therefore it helps it spin? I believe it is the only other force, so they must be the same?
6. ### Rotational Kinematics - Cylinder down a slope.

Homework Statement A certain non-uniform but cylindrically symmetric cylinder has mass 9 kg, radius 1.2 m, and moment of inertia about the center of mass 7.6 kg m2. It rolls without slipping down a rough 20° incline. What is the acceleration of the cylinder's center-of-mass...
7. ### KE of a rotational system

Thanks, :P. It needed that constant for a disk (1/2). Thanks for your help. :)
8. ### KE of a rotational system

Homework Statement A 15 kg uniform disk of radius R = 0.25 m has a string wrapped around it, and a m = 5 kg weight is hanging on the string. The system of the weight and disk is released from rest. a) When the 5 kg weight is moving with a speed of 1.7 m/s, what is the kinetic energy of the...
9. ### Momentum (Cannon fires at angle & recoils)

These are the hints they give me, I just don't understand at all what to do. I now believe though that the velocity I'm finding in the x-direction is incorrect, but I'm not sure why. HELP: Because the cannon is moving, you must find the speed of the projectile with respect to the ground...
10. ### Momentum (Cannon fires at angle & recoils)

q is typically the letter they use to denote theta, since I cannot input a theta symbol into my answer field. The field asks for "qground="
11. ### Momentum (Cannon fires at angle & recoils)

what do you mean "Then please label the 40 degrees"? If you're implying that the answer is 40 degrees, I can assure with certainty that it isn't. I input these values into my homework online, and it returns with either an "OK" or "NO". I've tried 40 degrees, that was my first guess. =/ So...
12. ### Momentum (Cannon fires at angle & recoils)

Homework Statement A circus cannon, which has a mass M = 5000 kg, is tilted at q = 40°. When it shoots a projectile at v0 = 80 m/s with respect to the cannon, the cannon recoils along a horizontal track at vcannon = 1 m/s with respect to the ground. 1. At what angle to the horizontal...
13. ### Conservation of Momentum and KE (bullet through a pop can)

Hey, thanks. That makes sense, I should have been thinking that simple. It worked out, thanks again. :)
14. ### Conservation of Momentum and KE (bullet through a pop can)

Homework Statement A bullet of mass 0.008 kg and initial speed 300 m/s penetrates an initially stationary pop can of mass 0.042 kg and emerges with a speed 210 m/s. What is the initial momentum of the bullet and pop can system? =2.4 kgm/s What is the final momentum of the bullet...
15. ### Work and Energy with centripedal acceleration and springs.

Homework Statement The two problems below are related to a cart of mass M = 500 kg going around a circular loop-the-loop of radius R = 15 m, as shown in the figures. All surfaces are frictionless. In order for the cart to negotiate the loop safely, the normal force exerted by the track on...