Physics - September 2007

Suppose that f'(x) = -g(x) and g'(x) = f(x) for all real x
a. Prove that f^2(x) + g^2(x) = C for some constant C.
b. Suppose that f(0) = 0 and g(0) = 1. What is C?

2007-09-24 17:32:27 · 1 answers · asked by Anonymous

Two particles each have a mass of 5.90 10-3 kg. One has a charge of +5.0 10-6 C, and the other has a charge of -5.0 10-6 C. They are initially held at rest at a distance of 0.95 m apart. Both are then released and accelerate toward each other. How fast is each particle moving when the separation between them is one-half its initial value?_______m/s

2007-09-24 17:18:22 · 2 answers · asked by Hera08 1

An object mass m dropped from a height h is moving at a velocity v just before ot hits the ground. If the acceleration of gravity is g, the average friction force acting on the object is...

Note: the answer is (2mgh-mv^2)/2h. I just need to know how to get there :-]]

2007-09-24 17:01:48 · 1 answers · asked by heyy ya 1

Harry is finding it very difficult to muster enough torque to twist a stubborn bolt with a wrench and he wishes he had a length of pipe to place over the wrench handle to increase his leverage. He has no pipe, but he does have some rope. Will torque be increased if he pulls just as hard on a legnth of rope tied to the wrench handle?

a) Yes
b) No

2007-09-24 16:34:40 · 4 answers · asked by ? 6

The frictional force is negligible. The block starts from rest and moves 14.0 m in 9.00 s.
(a) What is the mass of the block of ice?
kg

(b) If the worker stops pushing after 9.00 s, how far does the block move in the next 9.00 s?
m

2007-09-24 16:24:59 · 2 answers · asked by b_rad_geezy 1

A seagull, ascending straight upward at 5.20 m/s, drops a shell when it is 15.0 m above the ground.

(a) What is the magnitude of the shell's acceleration just after it is released?

______ m/s^2


(b) Find the maximum height above the ground reached by the shell.

______ m

(c) How long does it take for the shell to reach the ground?

______ s

(d) What is the speed of the shell at this time?

_______ m/s

2007-09-24 15:58:54 · 3 answers · asked by acousticplaya90 1

1.) A 66 kg person escapes from a burning building by jumping from a window 25 m above a catching net.
Air resistance exerts a 95 N force on the person during the fall.

Determine the person's velocity just before hitting the net.

I've tried lots of different formulas (obviously not the right ones) and keep getting two answers (22.1 and 20.4) each time, and they're both wrong. Please help; I don't know what I'm doing wrong.

2.) A block with a mass of 5 kg is held in equilibrium on an incline of angle 30.0° by the horizontal force, F. Find the magnitude of F.

This one is mind boggling. I really don't understand how to do any of it. And don't be all like, "do your own work," cause I'm asking for help, not answers.

Thanks.

2007-09-24 15:49:58 · 1 answers · asked by Steve Gaines 2

please tell me!! ASAP!!!!

2007-09-24 14:41:25 · 1 answers · asked by frazy13 2

Its so stupid and all the definitons give you big fancy explanations. Thanks

2007-09-24 14:39:01 · 3 answers · asked by El-Tino 2

A climber near the summit or a vertical cliff accidently knocks loose a large rock. She sees it shatter 8 s later at the bottom of the cliff. What was the speed of impact? How far did the rock fall?

2007-09-24 14:23:11 · 1 answers · asked by victoria r 1

When you weigh yourself on good old terra firma (solid ground), your wieght is 152 lb. In an elevator your apparent weight is 132 lb.

2007-09-24 14:21:11 · 1 answers · asked by Anonymous

2007-09-24 14:14:18 · 1 answers · asked by michael l 1

1. a) Describe the process(es) by which (i) energy is produced in the Sun (ii) energy is transferred from the Sun to Earth.
b) Compare the heat radiated by a hot body with the light emitted from a lamp under the following headings:
(i) speed of travel (ii) ability to pass through a vacuum (iii) ease with which they are reflected (iv) ease with which they are absorbed.

2007-09-24 13:49:46 · 1 answers · asked by fabulous and fly 1

A plane is flying South (270 degrees) @ 500 km/h with a strong wind from east at 45 km/hour. Find the velocity of the plane in reference to the ground

2007-09-24 13:39:03 · 2 answers · asked by Jennifer R 1

Member since: September 06, 2007
Total points: 20 (Level 1)
Points earned this week:
--% Best answer

miss_su_09
S Help please?
1.How much work can a 50.0 kg wrecking ball traveling at 5.00 m/s do on the building it strikes?
250
10
1,250
625

2A flower pot falls off a window ledge 10.0 m above the ground. Its velocity as it hits the ground is
unknown because we don't know the mass of the flowerpot.
20 m/s
14 m/s
10 m/s


3.A horizontal force of 275.0 N is exerted on a box with a weight of 745 N while moving it a distance of 2.0 m. How much work was done on the box? (calculate your answer in Newtons - just give me the number, no units in answer area) ?


4. A rock on the ground is considered to have zero potential energy. In the bottom of a well, then, the rock would be considered to have
no potential energy (all kinetic energy)
negative potential energy
zero potential energy, as before.
positive potential energy ?


5. If you do 600 J of work hoisting a 20 kg bale of hay, to what height did you lift it (in meters)?

2007-09-24 13:39:02 · 1 answers · asked by miss_su_09 1

1.calculate the speed of the bob at the next-to-last spark mark and
2.the d/t for the bob at the last spark mark
3.calculate the uncertainty in the d/t value for the last visible point

Using diagram
http://img524.imageshack.us/my.php?image=bobxt8.jpg

2007-09-24 13:37:53 · 1 answers · asked by Anonymous

2. A golf ball rebounds from the floor and travels straight upward with a speed of 5.0 m/s. To what maximum height does the ball rise?

4. ball is thrown vertically up. 8 s later it returns to point on release. wat is the initial velocity?

5. A diver springs upward with an initial speed of 1.8 m/s from a 3.0 m board, Find the velocity with which he strikes the water. What is the highest point he reaches above water?

I ahve these three formulas i keep trying i just dont kno wat to do with the numbers

2007-09-24 13:33:50 · 1 answers · asked by Anonymous

2007-09-24 13:24:09 · 8 answers · asked by fronny9 1

A block with a mass of 12 kg is held in equilibrium on an incline of angle 30 degrees by the horizontal force, F.

(a) Find the magnitude of F.

(b) Find the normal force exerted by the incline on the block. (disregard friction.)

2007-09-24 13:14:26 · 2 answers · asked by Anonymous

1) How do you find the mass of an object only knowing the speed of the object and the kinetic energy of the object
2)how do you find the speed of an object only knowing the kinetic energy and the mass
3)How to you find an objects speed at the end of something (a hill for example) only knowing the vertical drop and the mass of the object

2007-09-24 13:13:25 · 1 answers · asked by hawaiigrl 2

A ball is thrown upward from a building that is 100m tall

2007-09-24 13:12:25 · 1 answers · asked by John R 1

2007-09-24 13:08:32 · 7 answers · asked by Anonymous

I did these problems already, but I would like to check them. If you could let me know what you get so I can see if I'm doing them right or not.

1.) A bus slows down uniformly from 21 m/s to 0 m/s in 21s. How far does it travel before stopping?

2.) A worker drops a wrench from the top of a tower 80.0m tall. What is the velocity when the wrench strikes the ground?

Thanks

2007-09-24 12:57:59 · 2 answers · asked by neverisenough 1

2007-09-24 12:51:01 · 1 answers · asked by zahava60@sbcglobal.net 1

A truck is going from A to B.
the speed of the truck is 70km/hour
A cab is going from B to A.
the speed of the cab is 90 km/hour.
when will the two meet?
please show the way

2007-09-24 12:49:51 · 1 answers · asked by Anonymous

I know that the lifetime of a muon is about 2.2 microseconds. In terms of relativity, is that measured in the muon's reference frame, or the earth's reference frame? I'm doing a question about how a muon travelling at 0.99c from 10 km up in the atmosphere can make the 30 microsecond trip to the earth's surface within it's lifetime.

2007-09-24 12:47:13 · 2 answers · asked by jsprplc2006 4

race car driver makes pit stop and refuels, after refueling he leaves pit with acceleration whose magnitude is 6.0 m/second squared, and after 4.0 seconds he enters the main speedway. At the same instant, another race car that is on the speedway and traveling at a constant speed of 70.0 m/s overtakes and passes the entering car. If the entering car maintains its acceleration, how much time is required for it to catch the other car?

Ok so i setting it up as Vo=0 for driver 1, and a=6.0m/seconds squared. and t=4 seconds. Then for driver two i got a=0 since hes going at constant speed and V=70m/s. but which formula do i use?!

3. Suppose you are visiting a planet in a distant part of the galaxy. to determine the acceleration due to gravity on this planer, u drop a rock from height of 55m. The rock strikes the ground 1.9 seconds later. How many times greater is the acceleration due to gravity on this planet than that on earth?

55=1/2(a)(1.9)squared so 3 times greater?

2007-09-24 12:39:59 · 1 answers · asked by Anonymous

Why is body temperature 98.6 degrees farenheit

2007-09-24 12:28:15 · 5 answers · asked by Anonymous

If you were standing in a bus moving at a constant velocity would you have to lean in a certain way to compensate for the bus's motion? What is teh bus were accelerating?

2007-09-24 12:01:31 · 3 answers · asked by Anonymous

Im in physics and i was wondering how to find the mass of an object knowing only the objects height in meters and the gravitational potential energy?

2007-09-24 11:41:07 · 2 answers · asked by hawaiigrl 2