Michelle

A 20.0 cm long organ pipe is filled with air and is open at one end and closed at the other. The velocity of sound in air at 0 degree C is 331 m/s. What is the frequency of the third node?

Thank you!

A siren has a frequency of 718 Hz when it is at rest, whereas it has an apparent frequency of 876 Hz when it is moving toward a stationary observer. What is the speed of the siren in the latter case?

The answer is 61.9 m/s

I need help with the how-to, thank you.

A piece of aluminum is attached to a string and suspended in a pool of oil with density 840 kg/m^3. If the apparent weight of the aluminum is 670 N, what is the volume of the aluminum?

Answer = 0.0368 m^3

Please show how to get to this answer, thank you.

Consider a wooden block of density 650 kg/m^3 and volume 2.2 m^3. What force is required to hold it completely under water?

The answer is 7550 N

Please help me get there. Thanks.

A rectangular block of wood (density 725 kg/m^3) of height 26 cm floats in a lake. What is the height of the wood above the water level?

the answer is 7.15 cm

I need help getting there, thank you :)

Consider a box with a lid 1.2 m wide and 0.82 m long. If the inside of the box is evacuated (i.e., its pressure is zero), how much force is required to open the lid?

The answer is 99400 N

Thank you.

A diver stands at rest at the end of a 32 kg diving board. Find the total torque due to gravity on the diving board. Assume the mass of the board is uniformly distributed. (Assume that the mass of the diver is 91.0 kg and the length of the board is 4.1 m.)

http://www.webassign.net/giocp2/8-p-016.gif

The answer is 4300 N*m

I need help getting there! Please show the steps :)

A block is dropped onto a spring with k = 28 N/m. The block has a speed of 2.9 m/s just before it strikes the spring. If the spring compresses an amount 0.13 m before bringing the block to rest, what is the mass of the block?

The answer is 0.0432 kg, I need help getting there, please explain. Thank you.

A rock of mass 4.0 kg is tied to a string of length 1.7 m. The rock is held at rest as shown in the figure below so that the string is initially tight, and then it is released.

http://www.webassign.net/giocp1/6-p-049.gif

(b) What is the maximum tension in the string?

The answer is 46.5 N, I need help getting there, please explain. Thank you. Also, I calculated the speed of the rock when it reaches the lowest point to be 1.77 m/s, not sure if you'll need that, but there it is.

Consider the rock and string in the figure below. The string is fastened to a hinge that allows it to swing completely around in a vertical circle. If the rock starts at the lowest point on this circle and is given an initial speed vi, what is the smallest value of vi that will allow the rock to travel completely around the circle without the string becoming slack at the top? Assume the length of the string is 6.4 m.

http://www.webassign.net/giocp2/6-p-043.gif

Answer is 17.7 m/s

I need help getting there, please explain, thank you.

A skier of mass 116 kg starts from rest at the top of the ski slope of height 100 m shown in the figure below. If the total work done by friction is −4.5 x 10^4 J, what is the skier's speed when he reaches the bottom of the slope? (Figure not drawn to scale.)

http://www.webassign.net/giocp2/6-p-071.gif

Answer is 34.4 m/s

I need help getting there, please explain the work. Thank you.

Spin Out! An interesting amusement park activity involves a cylindrical room that spins about a vertical axis (figure below). Participants in the "ride" are in contact with the wall of the room, and the circular motion of the room results in a normal force from the wall on the riders. When the room spins sufficiently fast, the floor is retracted and the frictional force from the wall keeps the people "stuck" to the wall. Assume the room has a radius of 2.2 m, and the coefficient of static friction between the people and the wall is μs = 0.44

Picture: http://www.webassign.net/giocp1/5-p-026.gif

Question: Apply Newton's second law along both the vertical and the radial directions. Find the minimum rotation rate for which the riders do not slip down the wall.

The answer is 0.507 rev/s

Please explain to me how to do this problem. Thank you.

A sled is pulled with a horizontal force of 16 N along a level trail, and the acceleration is found to be 0.40 m/s^2. An extra mass m = 4.2 kg is placed on the sled. If the same force is just barely able to keep the sled moving, what is the coefficient of kinetic friction between the sled and the trail?

The answer is 0.107

Can someone show/explain to me how to get there? Thank you.

Consider the problem of kicking a soccer ball past a goalkeeper into the goal. You are 21 m away from the goal and kick the ball at an angle of 33° with respect to the horizontal, and the ball just passes over the goalkeeper's hands. Hint: The height of the goalkeeper is 2 m.

Find the initial speed of the ball. (Find this one first please.)

Then calculate how long it takes the ball to get from you to the goal.

Please explain and show the equations you used.

Sometimes my laptop doesn't show images all the way and there would be a band of pixelated stuff. If I open the picture in a new tap, it's still pixelated. However, if I open it in incog. it isn't pixelated. I don't think this has anything to do with my extensions because I turned them all off for incog. and regular. It doesn't happen to all pictures, but it is annoying.

Also, it happens to ads too...

Here is a picture of my screen: http://i50.tinypic.com/335487c.png

And this is a picture of my screen with the image opened in its own tab: http://i46.tinypic.com/2zi3n9e.png

You can see that the picture remains pixelated even when reloaded.

Sometimes gifs would cut out frames and be distorted, I think it's affected by the same thing that's affecting the images ):

I'll give 10 points to the person that helps with this!

Two particles are at the same point at the same time, moving in the same direction. Particle A has an initial velocity of 8.4 m/s and an acceleration of 3.5 m/s2. Particle B has an initial velocity of 3.6 m/s and an acceleration of 5.9 m/s2. At what time will B pass A?

Please explain and type out the equation you used, I'll give 10 points to the answer that does this. :)

What is the name of this sea shell? I need the genus name and the species name.

I'm thinking that maybe the genus name is Euhadra, but I may be wrong!

Here are some pictures of the shell:

The bottom side- http://img440.imageshack.us/img440/8490/10unknownf...

The top side- http://img96.imageshack.us/img96/5711/10unknown.jp...

Thank you! :)

Write the definition of a biconditional statement as a biconditional statement. Use the condition and converse within the statement to explain why you biconditional is true.

The curve described by the equation in polar coordinates r = θ + sin(2θ) for 0 ≤ θ ≤ π, where r is measured in meters and θ is measured in radians. The derivative of r with respect to θ is given by dr/dθ = 1 + 2cos(2θ).

b. Find the angle θ that corresponds to the point on the curve with x-coordinate -2.

c. For π/3 < θ < (2π)/3, dr/dθ is negative. What does this fact say about r? What does it say about the curve?

d. Find the value of θ in the interval 0 ≤ θ ≤ π/2 that corresponds to the point on the curve in the first quadrant with greatest distance from the origin. Justify your answer.

If you can't answer all, please just answer the ones you can? :) Thanks!