Physics - December 2006

2006-12-05 11:00:53 · 7 answers · asked by Anonymous

2006-12-05 10:52:57 · 4 answers · asked by malutty92 2

2006-12-05 10:50:18 · 5 answers · asked by Anonymous

A stream of water strikes a stationary turbine blade, as the drawing illustrates. The incident water stream has a velocity of +18.0 m/s, while the exiting water stream has a velocity of -18.0 m/s. The mass of water per second that strikes the blade is 20.0 kg/s. Find the magnitude of the average force exerted on the water by the blade.
___________ N

to do this do you have to find mass through the velocity, and which one.
then how would i determine acceleration to get force?

2006-12-05 10:33:13 · 1 answers · asked by lifewithgooli 1

Suppose you put a very large-diameter tires on your car. Then, you speedometer will show a speed that is:
a) higher than it actually is
b)lower that it acutally is
c)the same as with the original tires

2006-12-05 10:28:38 · 9 answers · asked by 2fishBLUEfish 3

Hydrogen is half as dense as helium. Therefore, the buoyant force on a hydrogen balloon is, compared to a helium balloon of the same volume, (Select one)


A) one quarter as big.

B) half as big.

C) the same.

D) twice as big.

2006-12-05 09:46:09 · 16 answers · asked by Justin D 1

2006-12-05 09:24:41 · 3 answers · asked by buddhasmash 2

i have a moving object that id like to stop, but instead of using another moving object to hit it from the opposite direction creating equal negative work, i have an object attached to it that creates a shock wave, kinda of like a firecracker attached to a ball. what units of measurement am i working with here?

2006-12-05 09:24:08 · 7 answers · asked by destroyer of worlds 1

I've learned the stuff about the compass and the magnet but i need more then that to convince me.

2006-12-05 09:20:28 · 4 answers · asked by Shane H 1

I read in my science book that the weight of air in a room is about 70 kg. How was the air in the room measured???
Just wondering.

2006-12-05 08:43:00 · 9 answers · asked by lemon drops 3

2006-12-05 08:14:32 · 5 answers · asked by jim h 1

QUESTION: a middle-aged man typically has poorer hearing than a middle-aged woman. in one case a woman can just begin to hear a musical tone, while a man can just begin to hear the tone only when its intensity level is increased by 7.8 dB relative to that for the woman. what is the ratio of the sound intensity just detected by the man to that just detected by the woman?

My Approach:

B(man) - B(woman) = 7.8 = 10log(I man/10^-12) - 10log(I woman/10^-12)

= 10log (I man/I woman)

7.8 = 10log(I man/I woman)

I man/ I woman = 6.03 <---is that a correct number?

2006-12-05 08:03:45 · 3 answers · asked by Anonymous

2006-12-05 08:02:47 · 3 answers · asked by Elmay 2

question: deep ultrasonic heating is used to promote healing of torn tendons. it is produced by applying ultrasonic sound over the affected area of the body. the sound transducer (generator) is circular with a radius of 1.8 cm, and it produces a sound intensity of 5.9 x 10^3 W/m^2. how much tiem is required for the transducer to emit 4800 J of sound energy?

My approach:
A = (3.14)r^2 = (3.14)(1.8^2) = 10.2 m^2
I = 5.9 x 10^3 W/m^2
E = 4800 J

I = P/A
5.9 x 10^3 = P/10.2
P= 60180 J/T

4800 J/ 60180 J/T = .0798 s <---final answer

2006-12-05 07:58:42 · 1 answers · asked by Anonymous

2006-12-05 07:11:37 · 1 answers · asked by DOOM 2

For example if a concord plane is fitted with external propellers for its thrust instead of its normal jet engine, assuming the propellers speed could be increased indefinitely will it fly supersonic? if not, why? since both external propellers and internal propellers are blades that pulls air and pushes it backward to thrust the plane forward.

If increasing the propellers speed indefinately can also make planes with external propellers fly supersonic, then why has is it not been made possible?

2006-12-05 07:08:08 · 4 answers · asked by bitrus d 1

2006-12-05 06:57:46 · 6 answers · asked by DOOM 2

A radioactive nucleus at rest decays into a second nucleus, an electron, and a neutrino. The electron and neutrino are emitted at right angles and have momenta of 9,30x10^-23 kg.m/s and 5,4x10^-23 kg.m/s respectively.
What are the magnitude and direction of the momentum of the second ( recoiling) nucleus?

2006-12-05 06:40:07 · 4 answers · asked by nice_ girl 1

1. a ball of mass 0,440kg moving east ( +x direction) with a speed of 3,30m/s collides head on with a 0,220kg ball at rest. If the collision is perfectly elastic what will be the speed and direction of each ball after the collision?


2. A squash ball hits a wall at a 45 degree angle. What is the direction. a) of the change in momentum of the ball. b) of the force on the wall?

2006-12-05 06:15:45 · 4 answers · asked by schoolgirl 1

2006-12-05 06:06:33 · 16 answers · asked by Anonymous

A 28-g rifle bullet traveling 230m/s buries itself in a 3,6 kg pendulum haning on a 2,8m long string, which makes the pendulum swing upward in an arc. Determine te vertical and horizontal components of the pendulum's displacement.

plzzzzzzzzzzzzz tell me in an easy way and which formula do have i to use. plzzz

2006-12-05 05:48:39 · 4 answers · asked by nice_ girl 1

High frequency radiation is able to penetrate solid material by virtue of the wavelength being far smaller than the interatomic distances of the lattice. In order for the radiation to be stopped, a photon needs a direct collision with an atom. In such instances the thickness and density of the material determine how effective a shield it is.

Yet, for EM radiation with higher wavelength, very thin conductive surfaces can act as a shield because of Gauss' Law which states that fields can't exist within an equipotential.

So my question is - what is the difference between these two scenarios in terms of photon absorption? Is there a different mechanism of absorption? Is there are different property of long wavelength photons? Why is a direct atomic collision not needed?

2006-12-05 05:43:14 · 4 answers · asked by Andy G 1

2006-12-05 05:41:56 · 1 answers · asked by Steel 2

2006-12-05 05:26:50 · 14 answers · asked by olapeju b 2

2006-12-05 05:08:33 · 7 answers · asked by Steel 2

2006-12-05 04:59:48 · 3 answers · asked by Steel 2

A 4 kg block slides down a frictionless incline making an angle of 28 degrees with the horizontal. The acceleration of gravity is 9.81 m/s2.
Find the work done by the gravitational force when the block slides 1.2 m along the incline (in Joules).
What is the total work done on the block (in Joules)?
What is the speed of the block after it has moved 1.2 m if it starts from rest (m/s)?
What is its speed after 1.2 m if it starts with an initial speed of 1.3 m/s (answer in m/s)?

Thanks. The solution to any or all of these questions would be extremely helpful.

2006-12-05 04:59:09 · 1 answers · asked by ponies in outer space 1

2006-12-05 04:55:45 · 3 answers · asked by Steel 2

2006-12-05 04:52:16 · 4 answers · asked by nuny 1

2006-12-05 04:33:34 · 4 answers · asked by tomw91 2