Physics - November 2007

I have been working on these for a while and cannot figure it out!

1 .A measure of the amount of matter in an object is _______.

2. Mass is often measured in _______.

3. A measure of how much space a sample of matter takes up is ______.

4. The ______ of an object is a measure of the force of gravity between Earth and the object.

5. As long as the conditoons such as _____ do not change, the density of a substance does not change.

6. Each _______ has its own density.

7. Engineers and scientists use _______ of matter when they design and build things.

8. Scientists use a quantity called the _____to measure force.

9. An objects weight depends on its _______ in the universe.

10. As more matter gets packed into the same amount of space, the matieral's density _______.

11. An object's ability to float is called its _______.
12. Objexts have anough buoyancy to float when they are less _______ than the liquid they are placed.

Thank you for answering the __!

2007-11-14 11:10:49 · 1 answers · asked by wolf.viper 1

How much work did the wrestler do on his opponent?

2007-11-14 10:43:56 · 3 answers · asked by navya 1

A football player picks up a football, runs with it, and then throws is to a teammate. Describe the work done on the ball.

2007-11-14 10:41:13 · 1 answers · asked by Katey 1

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 9.50*10E-23 kg·m/s, and 5.30*10E-23 kg·m/s, respectively. What is the magnitude and direction of the momentum of the second (recoiling) nucleus?
Magnitude?
____________ kg·m/s

2007-11-14 10:37:18 · 2 answers · asked by Anonymous

A 20.0-kg floodlight in a park is supported at the end of a horizontal beam of negligible mass that is hinged to a pole. A cable at an angle of 30.0° with the beam helps to support the light. Find (a) the tension in the cable and (b) the horizontal and vertical forces exerted on the beam by the pole.

if a picture would help, go here:
http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&q=a+fishing+pole+is+long+and+inclined+to+the+horizontal+at+an+angle+of+what+is+the+torque+exerted+by+the+fish+about+an+axis+perpendicular+to+the+page+and+passing+through&btnG=Search

and click on the second link; it is a microsoft word file, and it is problem # 22

2007-11-14 10:35:21 · 1 answers · asked by sccrsweetie 2

What must the emf in the figure be in order for the current through the 7.00-ohm resistor to be 1.76A? Each emf source has negligible internal resistance.
Figure: http://i239.photobucket.com/albums/ff92/anakris_24/yf_Figure_26_51.jpg

Appreciate the help :)

2007-11-14 10:33:31 · 3 answers · asked by Hannah 4

For the resistor network shown in the figure, the ohmmeter reads 20.2ohms. What is the resistance of the resistor X?
Figure: http://i239.photobucket.com/albums/ff92/anakris_24/yf_Figure_26_49.jpg

Thanks for the help :)

2007-11-14 10:31:16 · 2 answers · asked by Hannah 4

a) A resistance R2 is connected in parallel with a resistance R1. Derive an expression for the resistance R3 that must be connected in series with the combination of R1 and R2 so that the equivalent resistance is equal to the resistance R1.

b) A resistance R2 is connected in series with a resistance R1. Derive an expression for the resistance R3 that must be connected in parallel with the combination of R1 and R2 so that the equivalent resistance is equal to R1.

Thanks. Appreciate the help :)

2007-11-14 10:26:47 · 2 answers · asked by Hannah 4

A mechanical door opener is used to deliver a constant 65 W of power to a spring with k = 759 N/m for 3.5 s. If the spring was originally uncompressed, what is the compression of the spring (in centimeters) at the end of that time period?

2007-11-14 10:22:37 · 1 answers · asked by Anonymous

and its ratios with subatomic particles?

2007-11-14 09:55:19 · 3 answers · asked by Anonymous

an industrial process has a cooling operation.
a large amount of hot solution (4000kg)must be cooled from a temperature of 48 c degree to 40c degree by the addition of ice.
treating the solution as warm water (shc=42oooj/kg c).
how much ice should be added?
a) if the ice teperature = 0 c degree
b) if the ice came from a freezer at -20 c degree? thank you all.

2007-11-14 09:38:07 · 1 answers · asked by sktany12 2

A hockey puck is hit on a frozen lake and starts moving with a speed of 21 m/s. Exactly 5.00 s later, its speed is 4.9 m/s. Its acceleration is -3.22m/s^2. It travels 64.75m during this 5.00 s interval.

What is the average value of the coefficient of kinetic friction between puck and ice?

2007-11-14 09:20:44 · 2 answers · asked by Anonymous

a. What is the work input?

b. What is the MA of the machine?

c. What is the work output?

d. What is the efficiency of the machine?

-
My teacher, fails at teaching.
I would like to be able to understand how to solve this before our test :]
Please.

2007-11-14 09:13:07 · 1 answers · asked by xuchihasakurax 2

A fishing pole is 2.00 m long and inclined above the horizontal at an angle of 20.0°. A fish is pulling on it with a force of 100N 37-degrees below the horizontal. What is the torque exerted by the fish about an axis perpendicular to the page and passing through the hand of the person holding the pole?

should I just use Torque = r * FsinX where X is 57-degrees

thanks!

2007-11-14 09:10:52 · 1 answers · asked by sccrsweetie 2

a grinding wheel is in the form of a uniform solid disk of radius 6.94cm and a mass of 2.06kg. it starts from rest and accelerates uniformly under the action of the constant torque of 0.606N*m that the motor exerts on the wheel.

how long does the wheel take to reach its final operating speed of 1200 rev/min?

through how many revolutions does it turn while accelerating?

2007-11-14 09:10:13 · 1 answers · asked by Anonymous

a potters wheel (a thick stone disk of radius 0.500m and a mass of 125kg) is freely rotating at 50.0 rev/minute. the potter can stop the wheel in 6.00seconds by pressing a wet rag against the rim and exerting a radially inward force of 68.0N. find the effective coefficient of kinetic friction between the wheel and the rag.

2007-11-14 09:05:59 · 1 answers · asked by Anonymous

What is translational kinetic energy? What are some examples of it?

2007-11-14 08:50:03 · 0 answers · asked by Choice 2

It is said Lewis Carroll was perplexed by such puzzle.

Cable hangs over frictionless pulley, next to roof on which is nice bottle of Vodka.

Now weight which exactly balances monkey hanging on the other side is attached to a massless cable.


What would happen to the weight if monkey tries to climb up the cable?

Take everything in account, like friction, weight of cable ect.

2007-11-14 07:53:08 · 9 answers · asked by Yahoo! 5

At the Earth's surface a projectile is launched straight up at a speed of 9.6 km/s. To what height will it rise? Ignore air resistance and the rotation of the Earth.

2007-11-14 07:06:38 · 3 answers · asked by thegenuwineone 2

How much work is done by the Moon's gravitational field as a 940 kg meteor comes in from outer space and impacts on the Moon's surface?

2007-11-14 07:05:31 · 2 answers · asked by thegenuwineone 2

Is there any sensor or laser beam which could help me?

2007-11-14 06:57:46 · 3 answers · asked by Anonymous

I need this answer as soon as possible! And I am not kidding! Please help! ASAP! I need the answer to this question!

2007-11-14 06:44:48 · 11 answers · asked by Tyler R 1

An isolated 3 kg object initially at rest explodes into 3 fragments. One fragment hass a mass of .50 kg and flies off along the negative x axis at a speed of 2.8 meters per second, and another has a mass of 1.3 kg and flies off along the negative y axis at a speed of 1.5 m/s. What is the speed and direction of the third fragment?

2007-11-14 06:38:22 · 3 answers · asked by Sonny 1

http://img149.imageshack.us/my.php?image=44545464864654se5.gif
I have a conflict between math and physics.
T1 and T2 are strings that go from the ceiling and hold 8 kg.
(Gravity = 10 m/s in this calculations so 8kg=80Newton)
http://img149.imageshack.us/my.php?image...
angle A=60
angle B=53
I used the Law of sines:
so:
t2/sin53 = t1/sin 60
t1=t2*sin60/sin53=1.0842t2
t1=1.0842*t2
--------------------------------------...
but if I take the vectors and find how much each is pulling to the X axis and to the Y axis get that:
t1=t2*cos60/cos53=0.8...
Whats wrong?

2007-11-14 06:20:03 · 2 answers · asked by Amir B 1

a distance of 12 cm into the tree's trunk. What was the force exerted on the bullet in bringing it to rest?

2007-11-14 06:14:14 · 3 answers · asked by Anonymous

The blades in a blender rotate at a rate of 7400 rpm. When the motor is turned off during operation, the blades slow to rest in 3.5 s. What is the angular acceleration as the blades slow down? What is the amswer in rad/s^2

2007-11-14 06:05:33 · 2 answers · asked by jm988sps 1

And if so, wouldn't we already have seen people from the past or the future?

2007-11-14 05:47:33 · 3 answers · asked by Anonymous

I know what analogue signals are... just don't know the answer to this question!!

2007-11-14 05:24:35 · 2 answers · asked by anna 1

2007-11-14 05:23:04 · 1 answers · asked by anna 1

A 15.0 kg object moving in the +x direction at 5.5 m/s collides head-on with a 10.0 kg object moving in the -x direction at 4.0 m/s. Find the final velocity of each mass if:(a) the objects stick together, (b) the collision is elastic, (c) the 15.0 kg oject is at rest after the collision, (e) the 15.0 kg object has a velocity of 4.0 m/s in the -x direction after the collision.

I have the answers, but I dont understand how they were derived: (a) 1.7 m/s for both (b) -2.1 m/s, 7.4 m/s (c) 0, 4.3 m/s (d) 2.8 m/s, 0 (e) -4.0 m/s, 10.3 m/s

It doesn't matter if you can't get all of them. EVERY little bit helps.

2007-11-14 05:12:53 · 2 answers · asked by Rasheena E 1