Physics - October 2007

Help!!!

2007-10-29 09:06:27 · 3 answers · asked by Anonymous

2007-10-29 08:41:48 · 10 answers · asked by matt 1

If I have 2 pendulums suspended a distance "x" from each other on a piece of string and set one in motion with a direction perpendicular to the string the 2 pendulums are suspended from (its difficult to describe) then energy will be transferred between the 2 in the same way as the more classical setup of 2 pendulums coupled by a spring. My question is, can I use the same equations of motion for my modified setup, or would I have to work out the equations by using the Lagrange equations/by using Hooke's law from scratch?

2007-10-29 08:32:46 · 2 answers · asked by Anonymous

A water turbine operates from a water supply that is 100 ft above the turbine inlet. It discharges to the atmosphere through a 6-in. diameter pipe with a velocity of 25 ft/s. If the reservoir is infinite in size, determine the power out of the turbine if the density of water is 62.4 lbm/ft3.

2007-10-29 08:10:56 · 2 answers · asked by Anonymous

2007-10-29 07:54:59 · 1 answers · asked by Anonymous

2007-10-29 07:20:12 · 1 answers · asked by ukbg 1

2007-10-29 07:16:54 · 1 answers · asked by ukbg 1

2007-10-29 07:12:04 · 11 answers · asked by Chellie M 1

is it a reflection of the sea, or light reflectiong through nitrogen particles... or any others...

2007-10-29 06:58:46 · 45 answers · asked by Anonymous

this question has puzzled me for ages

2007-10-29 06:57:32 · 22 answers · asked by Anonymous

2007-10-29 06:41:08 · 2 answers · asked by Rebecca xxx 2

A long jumper leaves the ground at an angle of 20.0 degrees to the horizontal and at a speed of 11.0m/s.

(a.) How long does it take for him to reach maximum height?

(b.) What is the maximum height?







I'm stuck on how to do these. Thanks for the help!!!!! God Bless!

2007-10-29 06:39:59 · 1 answers · asked by Anonymous

A rocket moves striaght upward, starting from rest with an acceleration of 29.4m/s^2. It runs out of fuel at the end of 4.00seconds and continues to coast upward, reaching a maximum height before falling back to Earth.

(a.) Find the rocket's velocity and position at the end of 4.00seconds.

(b.) Find the maximum height the rocket reaches.






There was ten parts to this problem and I'm stuck on how todo these to.
Thanks sooo much for the help!!!!

2007-10-29 06:33:14 · 1 answers · asked by Anonymous

Can someone PLEASE recommend a good pyhsics website where I could look up 'moments' or tell me what they are or perhaps give me another name for them!

2007-10-29 06:12:12 · 2 answers · asked by Meryl 2

2007-10-29 06:03:42 · 8 answers · asked by mad_xpert 2

In his explanation of the threshold frequency in the photoelectric effect, Einstein reasoned that the absorbed photon must have the minimum energy required to dislodge an electron from the metal surface. This energy is called the work function () of that metal. What is the longest wavelength of radiation (in nm) that could cause the photoelectric effect in each of the following metals?
(a) Barium, = 4.3 10-19 J
nm
(b) Tantalum, = 6.41 10-19 J
nm
(c) Tungsten, = 7.16 10-19 J
nm

2007-10-29 05:44:44 · 1 answers · asked by jnester0289 1

A toy car is sliding with a kinetic energy of 3.9 J when it locks up its tires and slides for 74 cm, while a frictional force of 0.74 N acts against it. What is the kinetic energy (in Joules) of the car after this frictional work is done?

I'd appreciate it if anyone could offer some assitance.

2007-10-29 05:18:51 · 2 answers · asked by Anonymous

A bicycle has wheels of radius 0.26 m. Each wheel has a rotational inertia of 0.095 kg·m2 about its axle. The total mass of the bicycle including the wheels and the rider is 77 kg. When coasting at constant speed, what fraction of the total kinetic energy of the bicycle (including rider) is the rotational kinetic energy of the wheels?

2007-10-29 05:11:46 · 2 answers · asked by Anonymous

2007-10-29 05:09:53 · 5 answers · asked by biskits mom 1

The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.040 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.060 kg and is initially at rest. The collision is not head-on. After the collision, the two pucks fly apart with the angles shown in the drawing.


http://www.webassign.net/CJ/07_32.gif

2007-10-29 05:02:14 · 2 answers · asked by Jeff 4

A tennis ball is thrown vertically upward with an initial velocity of +8.0 m/s.

What will the ball's speed be when it returns to its starting point? and how long will the ball take to reach its starting?

2007-10-29 04:59:35 · 3 answers · asked by Anonymous

passes over a pulley and is then fastened to a hanging object with mass m2=10.0kg. Find the acceleration of each object and the tension in the cable.

2007-10-29 04:57:54 · 1 answers · asked by mary s 1

Many times, when I sit in front of a mirror, I cast my shadow on top of it, but when I notice the objects that are reflected on the mirror, there is no shadow on them. How can this happen?

2007-10-29 04:51:03 · 3 answers · asked by Buzz - Darwindidit 6

A 20.0kg- projectile is fired at an angle of 60.0 above the horizontal with a speed of 80.0 m/s. At the highest point of its trajectory, the projectile explodes into two fragments with equal mass, one of which falls vertically with zero initial speed. You can ignore air resistance.How far from the point of firing does the other fragment strike if the terrain is level?
How much energy is released during the explosion?

2007-10-29 04:49:27 · 3 answers · asked by Natiphy2007 1

2007-10-29 04:41:17 · 3 answers · asked by Tim M 1

PLEASE HELP ME!!!!!!!

2007-10-29 04:31:46 · 4 answers · asked by mrjmiller21 1

A. is conserved only if the enviroment is frictionless
B. definetly not conserved
C. definetly is conserved
D. is conserved only if the collusion is elastic

2007-10-29 04:29:58 · 5 answers · asked by MeDIGURU 1

Here's a question on ray optics.

We say that the focal length of a lens is half times the radius of curvature, right. Now, consider any lens(say convex), made of any material(say glass). Now a beam of light parallel to the principle axis, passes through the lens. All the rays in the beam will converge at a point, which we call the focus. For now, let us assume that the focal length of this particular lens is half time the radius of curvature of the lens. Now, take another lens whose structure is identical to that of the previous lens, i.e., it has the same radius of curvature and everything, the only difference being that this time the lens is made of a material that is denser than that of the previous lens. This time, if we pass a beam of light parallel to the principle axis through the lens, all the rays in the beam will converge at a different focus, with focal length shorter than that in case of the previous lens. So, we can see that, 2F is not=R.PLEAZZZZZZ COMMENT

2007-10-29 04:24:11 · 4 answers · asked by Anonymous

A mine car, whose mass is 510 kg, rolls at a speed of 0.5 m/s on a horizontal track, as the drawing shows. A 150 kg chunk of coal has a speed of 0.60 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.

tried this solution, but it doesnt work, any ideas?

m1V1 + m2V2=(m1+m2)V3

V3= (m1V1 + m2V2)/(m1+m2)
V3=(510 x 0.5 + 150 x 0.60)/(510 + 150)
V3=0.52 m/s

2007-10-29 04:19:24 · 1 answers · asked by Jeff 4

By means of a rope whose mass is negligible, two blocks are suspended over a pulley, as the drawing shows, with m1 = 12.2 kg and m2 = 43.4 kg. The pulley can be treated as a uniform, solid, cylindrical disk. The downward acceleration of the 43.4 kg block is observed to be exactly one-half the acceleration due to gravity. Noting that the tension in the rope is not the same on each side of the pulley, find the mass of the pulley.

Image: http://www.webassign.net/CJ/p9-42alt.gif

Anybody have any idea how to do this?

I would appreciate any help.

Thank You.

2007-10-29 04:15:02 · 2 answers · asked by Anonymous