Physics - August 2007

2007-08-30 01:20:54 · 5 answers · asked by Bill W 【ツ】 6

2007-08-30 01:13:34 · 3 answers · asked by emz e 1

A ball with radius .060m and mass 1.00 kg is attached by a light rod .400m in length to a second ball with radius .080m and mass 4kg.

a.Where is the center of gravity of this system?
b.Suppose the rod is uniform and has a mass of 2kg. Where is the system's center of gravity now?

2007-08-30 00:15:06 · 2 answers · asked by physics maniac 2

A flat grindstone of mass M=1000kg is mounted on a frictionless bearing so it can rotate freely about the vertical axis passing through its center. The grindstone has zero initial angular acceleration and has a radius of .5m. A string is tied around its periphery and is pulled with a constant force of 10N. Find...

a. Find the torque exerted by the string with respect to the center of the grindstone.
b. Find the angular acceleration.
c.Find how much string will have been unwound 10s after the force was initially applied.
d.Find the kinetic energy of the body.
e. Find the amount of power delivered during rotations.

2007-08-30 00:07:48 · 2 answers · asked by physics maniac 2

A woman of mass m stands at the edge of a solid cylindrical platform of mass M and radius R. At t=0, the platform is rotating with negligible friction at angular velocity ωo about a vertical axis through its center, and the person begins walking with speed v (relative to the platform) toward the center of the platform.

a. Determine the angular velocity of the system, as a function of time.
b.What will be the angular velocity when the woman reaches the center?

2007-08-29 23:58:16 · 1 answers · asked by physics maniac 2

this is about torque,,,A magnetic tape is being played on a cassette disk. the tension in the tape applies a torque to the supply reel. assuming the tension remains constant during playback, discuss how this torque varies as the reel becomes empty.

2007-08-29 22:05:32 · 5 answers · asked by Anonymous

2007-08-29 20:11:39 · 6 answers · asked by Anonymous

2007-08-29 18:54:33 · 3 answers · asked by Sidereal Hand 5

why do we say Newton's Law and not principle while we say Archimedes principle and not law?

2007-08-29 18:28:58 · 2 answers · asked by avkd_sivakumar 1

if we round it to 10, it will have only 1 significant figure. If i round it to 10.0 it will have 3 of them.

2007-08-29 17:48:37 · 9 answers · asked by raj 2

A truck travels 14 blocks north, 16 blocks east, and 26 blocks south. What is its final displacement from the origin (magnitude and direction)? Assume the blocks are equal length.

2007-08-29 17:34:53 · 2 answers · asked by mai t 1

readings if temperature is measured in kelvins? Why if degrees are measured for angles?

2007-08-29 17:07:10 · 7 answers · asked by lilys.petal 2

If a cord is plugged into a receptical (outlet) there is electricity inherent ... I know that breaking the circuit stops the flow but I also know that current doesn't run back into the outlet, so what happens to it? does it just disappear?

2007-08-29 15:41:21 · 4 answers · asked by pickle head 6

i need answers a.s.a.p please. i beg you

2007-08-29 15:18:14 · 4 answers · asked by yungone 2

i have some practice questions on dimensionally correct equations that i just can't understand.

1. v^2 = v0^2 + 2ax

and

2. x = v0t + 1/2 * a^2 * t^2

i know x =length (L)
and a = acceleration (L/T^2)
and v & v0 = velocity (L/T)
and t = time (T)

i just don't understand how to put everything together.work would be appreciated due to the fact that i'm trying to figure out how to do this problem, i don't want just the answer. THANKS! :)

2007-08-29 15:09:21 · 3 answers · asked by bluenecklace 2

A spring is compressed between two toy cars (m1 = 120 g, m2 = 180 g), which are placed on the floor and released. It takes the spring 0.064 s to push the cars apart, after which they move directly away from each other, car 1 at a constant speed of 2.4 m/s.

(a) Calculate car 2’s speed after the spring is fully relaxed.
(b) Calculate the average force the spring exerted on car 1 while pushing the cars apart.

2007-08-29 14:13:04 · 1 answers · asked by wake up 1

A car in a repair shop is moved 2.45 m by a hydraulic lift. The work done on it by gravity is -43.9 kJ. What is the car's mass, and which way did it move?
1620 kg, down
1940 kg, up
1830 kg, up
2110 kg, down

2007-08-29 14:09:48 · 1 answers · asked by Anonymous

An 950-kg motorcycle drives east at 12 m/s, and an 1840-kg car drives west at 8.0 m/s. Calculate the total momentum of this two-vehicle system, assuming east is the +x direction.
-2100 kg m/s
-3300 kg m/s
-4900 kg m/s
-5600 kg m/s

2007-08-29 14:07:57 · 1 answers · asked by Anonymous

You have a closed shoe box with two strings protruding from either side. By pulling on the right string you can pull out 60cm of string. By pulling on the left string you can pull out 6cm of string. *When you pull on either string the opposite string disappears into the box, before you actually pulled out the said length. How is this possible? What is inside the box that causes this? Please Help!!!

2007-08-29 14:06:58 · 2 answers · asked by Soccer37 2

A pulley is attached to the ceiling. Spring scale A is attached to the wall and a rope runs horizontally from it and over the pulley. The same rope is then attached to spring scale B. On the other side of scale B hangs a 120-N weight. What are the readings of the two scales A and B? The weights of the scales are negligible.

These are the choices I have narrowed it down to:
A.) A reads 0; B reads 120N
B.) Both scales read 120N
C.) A reads 120 N; B reads 0

2007-08-29 14:04:49 · 2 answers · asked by triciawin87 2

If the force of repulsion between two protons is equal to the weight of the protron, how far apart are the protrons?
Mass of protron is: 1.6 x 10(-27) kg and the Charge of the protron is: 1.6 x 10(-19) C
PLEASE SHOW WORK AND PLEASE HELP!!!

2007-08-29 13:49:34 · 2 answers · asked by Nate 2

A police car is at rest when a speeder traveling at a constant 110km/h passes by. The police car takes off in hot pursuit the instant the speeder passes by. It catches up to the speeder in 700m, maintaining a constant acceleration.

2007-08-29 13:27:27 · 1 answers · asked by mm 2

Faced with an emergency situation, the driver jams on the brakes, and the car skids to a stop. What will be the cars stopping distance for (1) dry pavement and (2) wet pavement?

2007-08-29 12:45:51 · 1 answers · asked by Pascal 4

0.400 respectively. (1) What is the acceleration of the object if a 250-N horizontal force is applied to the box? (2) What is the acceleration if the applied force is 235-N?

2007-08-29 12:42:22 · 2 answers · asked by Pascal 4

One of the fundamental laws of motion states that the acceleration of an object is directly proportional to the resultant force on it and inversely proportional to its mass. From this statement, determine the dimensions of force.

Whats the answer?

2007-08-29 12:40:32 · 2 answers · asked by Brittney C 1

surface is 0.69, what horizontal force is required to get the crate moving?

2007-08-29 12:38:28 · 2 answers · asked by Pascal 4

2007-08-29 12:35:45 · 8 answers · asked by jamie d 2

A 74-kg biker accelerates from rest to a final speed v. If the total work done on her during that interval is 3000J, what is v?

2007-08-29 12:21:01 · 1 answers · asked by Anonymous

1. A flat circular plate of copper has a radius of .383 m and a mass of 27.7 kg. What is the thickness of the plate? Answer in units of m.
(please show work so i can learn the steps. THANK YOU)

2) The mass of the planet Saturn is 5.64 X 10 to the 26 power kg and its radius is 6 X 10 to the 7 power. Calculate its density. Answer in units of km/m to the 3rd power

(please show work/steps of how you came to the solution - thank you.)

3.)Water flows into a swimming pool at the rate of 9.27 gal/min. If the pool dimensions are 33.4 ft wide, 43.1 ft long, and 15.1 ft deep, how long does it take to fill the pool? (1 gallon = 231 cubic inches). Answer in units of minutes.

(THANK YOU PEOPLE - please show work )

2007-08-29 12:18:40 · 2 answers · asked by mimi j 1

A worker can apply force up to 500 N in any direction.
Coefficient of friction is μ=1/3.

2007-08-29 10:27:25 · 4 answers · asked by Alexander 6