# Search results

1. ### Shear Modulus of jiggling jello

Homework Statement A student bumps into a tray of jello. The lime jello is jiggling side to side faster than the orange jello. Both jellos have the same spatial dimensions. Which statement is true? Answer: Lime jello has a higher shear modulus than orange jello Homework Equations...
2. ### DNA waves and water

"DNA waves and water" Hello all, I've tried to keep in touch with the physics world in my life beyond academics and I came across this paper: http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.5166v1.pdf On one hand I think "this guy is a Nobel prize winner" and on the other hand I am...
3. ### Archived Series RLC circuits

Homework Statement A series RLC circuit has a 0.19 mF capacitor, a 16 mH inductor, and a 10.0 resistor, and is connected to an ac source with amplitude 9.0 V and frequency 60 Hz. (a) Calculate the voltage amplitudes VL, VC, VR, and the phase angle phi . VL = V VC = V VR = V...
4. ### Kirchhoff's circuit laws

Homework Statement http://img207.imageshack.us/img207/1685/p1854altco4.gif [Broken] Find the unknown emf and the unknown currents in the circuit below, in which R = 3.48 . Take the positive direction for current flow in each branch to be upwards. EMF = V left branch= A right branch=...
5. ### Dielectric help

[SOLVED]Dielectric help Homework Statement To make a parallel plate capacitor, you have available two flat plates of aluminum (area = 180 cm2), a sheet of paper (thickness = 0.10 mm, k= 3.5), a sheet of glass (thickness = 2.0 mm, . k= 7.0), and a slab of paraffin (thickness = 10.0 mm, k=...
6. ### Electric Fields.

Homework Statement Two equal charges (Q = +0.80 nC) are situated at the diagonal corners A and B of a square of side x = 1.2 m as shown in the diagram. What is the magnitude of the electric field at point D? Homework Equations E=kQ/r^2 The Attempt at a Solution First I converted...
7. ### Harmonic motion

Homework Statement A 171 g object on a spring oscillates left to right on a frictionless surface with a frequency of 3.00 Hz and an amplitude of 11.0 cm. (a) What is the spring constant? N/m (b) If the object starts from rest at x = 11.0 cm at t = 0 and the equilibrium point...
8. ### Youngs modulus stress/strain.

Homework Statement The figures below shows the forces acting on a tibia (shinbone, the long vertical bone in the figure) when a person stands on the ball of one foot. As shown, the force of the tibia on the ankle joint for a person (of weight 750 N) standing this way is 2800 N. The ankle...
9. ### [difficult] bernoulli's equation

Homework Statement In an aortic aneurysm, a bulge forms where the walls of the aorta are weakened. If blood flowing through the aorta (radius 1.1 cm) enters an aneurysm with a radius of 3.1 cm, how much on average is the blood pressure higher inside the aneurysm than the pressure in the...
10. ### Acceleration of hollow sphere rolling down table.

Homework Statement A hollow spherical shell is rolling without slipping or sliding down a board that is tilted at an angle of 35.0° with respect to the horizontal. What is its acceleration? Homework Equations I=2/3mr^2 if an object rolls without slipping or sliding: v = rw...
11. ### Linear and angular acceleration of a falling cylinder? [long]

Homework Statement http://img248.imageshack.us/img248/1639/cylinderjl0.jpg [Broken] A uniform cylinder with a radius of R and mass M has been attached to two cords and the cords are wound around it and hung from the ceiling. The cylinder is released from rest and the cords unwind as the...
12. ### Diving board and torque problem

Homework Statement A uniform diving board, of length 5.0 m and mass 52 kg, is supported at two points; one support is located 3.4 m from the end of the board and the second is at 4.6 m from the end (see the figure below). What are the forces acting on the board due to the two supports when a...
13. ### Rotational kinetic energy of a bike wheel

Homework Statement A bicycle has wheels of radius 0.29 m. Each wheel has a rotational inertia of 0.091 kg·m^2 about its axle. The total mass of the bicycle including the wheels and the rider is 79 kg. When coasting at constant speed, what fraction of the total kinetic energy of the bicycle...
14. ### Center of Mass problem

[Solved]Center of Mass problem Homework Statement Jane is sitting on a chair with her lower leg at a 30.0° angle with respect to the vertical, as shown. You need to develop a computer model of her leg to assist in some medical research. If you assume that her leg can be modeled as two...
15. ### Conceptual question on momentum

Homework Statement An astronaut is on a space walk when his tether breaks. He has no rocket pack, only a big wrench. How does he get back to the ship? Homework Equations p=mv The Attempt at a Solution I have no idea. I imagined him using the wrench as some sort of "paddle" as he...
16. ### What is the velocity of the cars right after the collision?

Homework Statement A 1500 kg car moving east at 17 m/s collides with a 1610 kg car moving south at 15 m/s and the two cars stick together. (a) What is the velocity of the cars right after the collision? (b) How much kinetic energy was converted to another form during the collision...
17. ### Elephant in the way kinetic energy problem.

"Elephant in the way" kinetic energy problem. Homework Statement http:/www.imgred.com/http://static.scribd.com/docs/736egzypod07v_files/image004.jpg I found this on one of those "OMG FUNNY" internet web pages. I am trying to attempt a solution. Homework Equations Mechanical energy is...
18. ### Car rolling down a hill. How high will it go up another incline?

Homework Statement A 684 kg automobile is moving at 13.2 m/s at a height of 5.0 m above the bottom of a hill when it runs out of gasoline. The car coasts down the hill and then continues coasting up the other side until it comes to rest. Ignoring frictional forces and air resistance, what is...
19. ### Two problems involving angular velocity:

Two problems involving angular velocity: Edit: Problem one solved! Hooray! 2.The Milky Way galaxy rotates about its center with a period of about 192 million years. The Sun is 2x10^20 m from the center of the galaxy. How fast is the Sun moving with respect to the center of the galaxy...
20. ### Static friction forces on ramp

An 55.0-N crate of apples sits at rest on a ramp that runs from the ground to the bed of a truck. The ramp is inclined at 30.0° to the ground. I sketched the problem using a popular paint program. I seem to be having problems visualizing components of the normal force for some reason. I know...
21. ### Kinetic friction.

Homework Statement An 60-kg skier is sliding down a ski slope at a constant velocity. The slope makes an angle of 11° above the horizontal direction. (a) Neglecting any air resistance, what is the force of kinetic friction acting on the skier? (b) What is the coefficient of kinetic...