Physics - January 2007

If the output work of a simple machine equals the input work, the machine is said to have ____________ efficiency.

2007-01-30 16:27:03 · 3 answers · asked by <333 3

2007-01-30 16:19:36 · 3 answers · asked by presentraj 1

2007-01-30 16:09:37 · 8 answers · asked by chijliak 1

a- depends on the mass
b- corresponds to a KE equal to its rest energy
c- is the speed of sound
d- is the speed of light

2007-01-30 15:59:38 · 6 answers · asked by Tami B 1

Iron has a property such that a 1.00 {\rm m}^{3} volume has a mass of 7.86 \times 10^{3} {\rm kg} (density equals 7.86 \times 10^{3} {\rm kg/m^3} ). You want to manufacture iron into cubes and spheres.

2007-01-30 15:51:17 · 2 answers · asked by Anonymous

A rocket rises vertically, from rest, with an acceleration of 2.4 m/s2 until it runs out of fuel at an altitude of 1400 m. After this point, its acceleration is that of gravity, downward.

(a) What is the velocity of the rocket when it runs out of fuel?
I calculated this to be 81.9 m/s
(b) How long does it take to reach this point?
I calculated this to be 34.1 s
(c) What maximum altitude does the rocket reach?
I need help with this one.....answer should be in meters.
(d) How much time (total) does it take to reach maximum altitude?
Need help here too. Answer should be in seconds.
(e) With what velocity does the rocket strike the Earth? (Assume up is positive.)
________________m/s
(f) How long (total) is it in the air?
_________________ s

2007-01-30 15:46:31 · 4 answers · asked by Jessie L 2

We were asked to do an exhibit that is interactive and interesting. Anything about physics! :D

2007-01-30 15:44:50 · 5 answers · asked by Anonymous

I asked this questions before, in a bit of a different way. the most objection was the electrons dont orbit around the nucleus like planets around the sun, there in a kind of cloud. but there are actully spining things in atoms Iv been lead to belive. So could this be happening. bcos of the size difference it would be spining so fast in our view that it would look like a cloud to us.

2007-01-30 15:42:44 · 6 answers · asked by marvin b 1

A rocket fires two engines simultaneously. One produces a thrust of 760 N directly forward while the other gives a thrust of 472 N at an angle 16.8^\circ above the forward direction.

2007-01-30 15:38:59 · 1 answers · asked by Anonymous

Is there ever a time at which a small magnetic field can eventually saturate magnetic shielding of very high quality such as MuMetal? Or can magnetic shielding block the magnetic field indefinitely? Would layers help?

2007-01-30 15:29:07 · 4 answers · asked by What_a_what 2

2007-01-30 15:26:24 · 8 answers · asked by michael n 1

2007-01-30 15:21:10 · 5 answers · asked by Buck BUCK 2

2007-01-30 15:19:55 · 4 answers · asked by urbabbiemexagee 1

You're d1=7.09 m from one wall of a house. You want to toss a ball to your friend who is d3= 7.09 m from the opposite wall. The house is d2=7.09 m wide and has a height of h1=3.12 m. The throw and catch each occur h2= 1.02 m above ground. What minimum speed will allow the ball to clear the roof?

WHAT DO I DO? i'm looost

2007-01-30 15:12:08 · 2 answers · asked by theleprechaunsarecoming 1

A boat moves through the water with two forces acting on it. One is a 2.62x10³ Newtons (N) forward push by the motor, and the other is a 1.70 x 10³ N resistive force due to the water.

a) What is the acceleration of the1349.4 kg boat? Answer in units of m/s²

b) If it starts from rest, how far will it move in 13.5 s? Answer in units of m.

c) What will its speed be at the end of this time interval? Answer in units of m/s.


My teacher is not very understanding. I have been absent for a week for a family funeral and I really do not understand what has been going on in physics class. Please help me solve any of these or all of them and show how you got the answer. ANYTHING helps. Thank you so much!

2007-01-30 14:59:27 · 2 answers · asked by susie q 2

A basket ball player running at 6.0 m/s slides into home plate and stops in 2.5 s.What is the average acceleration of the baseball player?
show your work.
to get full point

2007-01-30 14:48:43 · 8 answers · asked by Anonymous

A roller coaster car accelerates at 8.0 m/s for 4.0 s.What is the change in the speed of the roller coaster car?
show me the work?

2007-01-30 14:41:51 · 3 answers · asked by Anonymous

In a road test,car A accelerates from rest (0km/h)to 100.0 km/h in 16.0 and car b takes 8.0s in the same test.Which car has the greater average acceleration?By how many times?
show me the work please.

2007-01-30 14:34:38 · 4 answers · asked by Anonymous

True or False? If false, write the correct term that's in UPPERCASE.

According to present atomic theory, the location of an ELECTRON in an atom is best represented by a probability cloud.

The mass of an ELECTRON is about equal to the mass of a proton.

Two isotopes of carbon are carbon-12 and carbon-14. These isotopes differ from one another by two ELECTRONS.

NONMETALS are poor conductors of heat and electricitiy.

Seven electrons in the outermost energy level is a characteristic of a METAL.

2007-01-30 14:25:21 · 4 answers · asked by aimeeish 2

If you were on a plane going down, not taking into account wind and such, lets say you were standing on top of it, and thusly would be falling at the same speed. If you jumped upwards like two feet before it crashed, not taking into account flames and such, would you live? It seems sorta like you could, cause the world is constantly spinning, and it's the same sort of idea--you take ont eh energy and movement of the larger object you're on, but when you jump you seperate yourself from it and would start over--two feet above ground.
Ideas?

2007-01-30 14:22:03 · 16 answers · asked by the_akbash 1

Carol drops a stone into a mine shaft 394 meters deep. How soon after she drops the stone does she hear it hit the bottom of the shaft?

2007-01-30 14:02:34 · 6 answers · asked by eldiablo049@sbcglobal.net 1

He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 2.8 kg physics textbook horizontally toward the north shore at a speed of 5.0 m/s. How long does it take him to reach the south shore?

2007-01-30 13:57:29 · 1 answers · asked by Anderson W 1

Id like to know the averge size difference. it might be such a difference that what we see in our univers and compar it to the atomic level, ends up being like the history of our univers happening in ten seconds at the atomic level.

2007-01-30 13:48:17 · 4 answers · asked by marvin b 1

Junes Verne in 1865 suggested sending people to the Moon by firing a space capsule from a 245 m long cannon with a launch speed of 10.37 km/s. What would have been the unrealistically large acceleration experienced by the space travelers during launch?

2007-01-30 13:29:07 · 2 answers · asked by chrisamethyst 4

6.When you burn a log in the fireplace, the resulting ashes have a mass less than that of the original log. Account for the difference in mass.

2007-01-30 13:26:29 · 2 answers · asked by Celia 4

As we all know the fourth dimension is time..... Einstein prompted it to equal footing as space.

Is it really possible to visualise 4 dimensions?

2007-01-30 13:05:34 · 5 answers · asked by sh 1

A kangaroo jumps to a vertical height of 2.5 m. How long was it in the air before returning to Earth?

Answer should be in seconds.

2007-01-30 12:57:51 · 3 answers · asked by Jessie L 2

2007-01-30 12:42:37 · 4 answers · asked by J 6

I have been researching and I know that the difference is 50 but would the correct answer be 50 or 10\5 (10 to 5th power) :)
what is the difference?

2007-01-30 12:40:49 · 5 answers · asked by bellaandbobby 2

2007-01-30 12:37:33 · 3 answers · asked by angie 1