A top-loading washing machine has a cylindrical tub that rotates about a vertical axis. The tub of one such machine starts from rest and reaches an angular speed of 2.0 rev/s in 7.0 s. The lid of the machine is then opened, which turns off the machine, and the tub slows to rest in 11.0 s. Through how many revolutions does the tub turn during this 18 s interval? Assume constant angular acceleration while it is starting and stopping.

Two charges are located in the ?–? plane. If ?1=−3.20 nC and is located at (?=0.00 m,?=0.640 m), and the second charge has magnitude of ?2=3.80 nC and is located at (?=1.50 m,?=0.550 m), calculate the ? and ? components, ?? and ??, of the electric field, ?⃗ , in component form at the origin, (0,0). The Coulomb force constant is 1/(4??0)=8.99×109 N⋅m2/C2.

A dipole moment, p = (2 Cm i) + (-5 Cm j) + (7 Cm k), is within an E = (-5 N/C i) + (6 N/C j) + (3 N/C k).

- Determine the potential energy stored by the dipole in the field.
- Determine the torque on the dipole by the field.
- Determine the angle between the dipole moment and the field.

explain how the rate of change of flux affects the induced E.M.F. in a conductor

A) What will a spring scale read for the weight of a 54-kg woman in an elevator that moves upward with constant speed 5.0 m/s?

B) What will a spring scale read for the weight of a 54-kg woman in an elevator that moves downward with constant speed 5.0 m/s?

C) What will a spring scale read for the weight of a 54-kg woman in an elevator that moves upward with acceleration 0.35g?

D) What will a spring scale read for the weight of a 54-kg woman in an elevator that moves downward with acceleration 0.35 g ?

E) What will a spring scale read for the weight of a 54-kg woman in an elevator that moves in free fall?

Three resistors are connected in series across a battery. The value of each resistance and its maximum power rating are as follows: 6.6Ω and 17.2 W, 34.6Ω and 12.0 W, and 20.0Ω and 12.6 W. (a) What is the greatest voltage that the battery can have without one of the resistors burning up? (b) How much power does the battery deliver to the circuit in (a)?

Hello,
I'm using Halliday and Resnick's Fundamentals of Physics, 10th edition. It has some equations in it that seem to contradict each other. I know the problem is with me though, not the equations. Electric potential energy is given as U=VQ (equation 24-3), where Q is charge and V is voltage. We also have the equation, Q=CV (equation 25-1), where C is capacitance. So, it looks like we could say U=CV^2 (substituting CV from 25-1 for Q in 24-3). I know that we cannot, since U=1/2CV^2 (equation 25-22), but I don't see where the problem in my reasoning is.... any help would be appreciated! (Barney style please!)   Thanks!

Darrell

Ball 1, with a mass of 159 g and traveling at 11.0 m/s , collides head on with ball 2, which has a mass of 324 g and is initially at rest. Assume that ball 1 is traveling to the right before the collision and that the collision is one dimensional.

What is the final velocity of ball 1 if the collision is perfectly elastic?

Answer: -3.76 m/s

What is the final velocity of ball 2 if the collision is perfectly elastic?

Answer: 7.24 m/s

What are the final velocities of the combination if the balls stick together?

Answer: 3.62

How much KE was lost when the balls stuck together?

Use Maple to solve the problem shown below. (I know, the math is pretty easy, but that's not the point. The point is to test the capabilities of BbLearn.) Save your Maple worksheet to a PDF file and upload it here.

Note: To enter Comments into your Maple Worksheet, precede the comment with the # symbol. For example:

>f:=a*x^2+b*x+c=0;#This is a quadratic polynomial

The first part (>f:=a*x^2+b*x+c=0; ) is the Maple expression, and the second part (#This is a quadratic polynomial) is a comment.

Problem:

Pt has a work function larger than almost any other metal, 6.35 eV. What is the longest wavelength of light that can dislodge an electron from Pt metal?

A basic electrical circuit consists of a battery, a light bulb, a switch and wires connecting them. As soon as the switch is closed, even the light bulb is one mile away, the light bulb will be on IMMEDIATELY.  This means that the electrical current (made of moving electrons) starts to run everywhere in the wire as soon as the switch is closed . Explain what happen and the source(s) of these free moving electrons.

Two cars approach each other. Initially they are separated by 1000 m. One car accelerates at 2 m/s^2 from rest. The other car travels at a constant speed of 20 m/s. Draw distance indicating how far from each of the cars' starting point the cars will collide.

Many chemical reactions release energy. Suppose that at the beginning of a reaction, an electron and proton are separated by 0.135 nm , and their final separation is 0.105 nm .

How much electric potential energy was lost in this reaction (in units of eV)?

A particle with charge 7 µC is located on the x-axis at the point −4 cm , and a second particle with charge 4 µC is placed on the x-axis at 8 cm . What is the magnitude of the total electrostatic force on a third particle with charge −4 µC placed on the x-axis at 2 cm ? The Coulomb constant is 8.9875 × 109 N · m2 /C 2 . Answer in units of N.

How can you tell if an object is charged? Explain using induction or conduction or friction.

A stone is dropped into a river from a bridge at a height h above the water. Another stone is thrown vertically down at a time t after the first is dropped. Both stones strike the water at the same time. What is the initial speed of the second stone? Give your answer in terms of the given variables and g.