Physics - October 2007

When you push a 1.70 kg book resting on a tabletop it takes 2.40 N to start the book sliding. Once it is sliding, however, it takes only 1.50 N to keep the book moving with constant speed. What are the coefficients of static and kinetic friction between the book and the tabletop?

Static?

Kinetic?

If you can just tell me to go about how to solve the problem that would be fine. (Though answers are always welcome to.) I am drawing a complete blank.

2007-10-11 05:05:47 · 4 answers · asked by lstntht 1

2007-10-11 04:42:22 · 4 answers · asked by Anonymous

A load of bricks with mass = 15.0 kg hangs from one end of a rope that passes over a small, frictionless pulley. A counterweight of mass m2= 28.0kg is suspended from the other end of the rope, as shown in the figure. The system is released from rest.What is the magnitude of the upward acceleration of the load of bricks?
Take the free fall acceleration to be = 9.80m/s^2 .What is the tension in the rope while the load is moving?
Take the free fall acceleration to be = 9.80m/s^2 .

2007-10-11 04:39:59 · 5 answers · asked by Natiphy2007 1

the greater pressure amplitude and by what factor is it greater? B) What is the ratio of their intensities?

2007-10-11 04:34:28 · 2 answers · asked by Karma H 1

per second? B)At this rate, how long would it take yur eardrum to recieve a total energy of 1.0J? Please show work! Thank you*

2007-10-11 04:26:31 · 1 answers · asked by Karma H 1

what is the percentage change in kinetic energy of a sattelite required to make it leave its orbit and escape to infinity.

2007-10-11 04:23:01 · 8 answers · asked by sameerteacher01 1

2007-10-11 02:46:57 · 6 answers · asked by titam 1

can you give me some hydrodynamic problems (physics) for me to solve?

2007-10-11 02:41:37 · 2 answers · asked by narcoleptic alky 1

If a baseball pitch was thrown horizontally and the ball falls .809m by the time it reaches home plate 18.3 m away how fast was the pitch? the time of flight? Calculate the initial horizontal velocity.

2007-10-11 02:12:36 · 1 answers · asked by Thomas L 1

The air in a hot-air balloon at 754 torr is heated from 13°C to 60.0°C. Assuming that the moles of air and the pressure remain constant, what is the density of the air at each temperature? (The average molar mass of air is 28.8 g/mol.)
13°C

60.0°C

2007-10-11 01:42:40 · 1 answers · asked by jnester0289 1

i am doing a science fair project on which kind of sound barrier works best and i need to figure out how i would measure the sound waves.

2007-10-11 01:13:30 · 3 answers · asked by the crazyness 2

Do you believe that this world has many dimensions?
1) Physical and Spiritual Dimension
2) Naturalistic and Imaginary Dimension
3) Dimension of Time (1 second is 1 dimension)
4) Dimension of Size (Microscopic to universal)
5) Dimension of Physics (Quantum Physics and Newtonian Physics)
Does these dimensions abstractly exist?

2007-10-11 01:08:37 · 5 answers · asked by Kyle J 6

2007-10-11 00:12:45 · 2 answers · asked by star 2

this is the situation: a body of mass starts down from the top of an inclined plane 20 ft long and 10 ft high. what is its velocity at a point 12 ft from the top if the coefficient of friction is 0.1?

sorry for the pressure. thanks a lot. it will be really a big help.

2007-10-11 00:11:45 · 3 answers · asked by glacylyn e 1

sorry for the pressure. but can someone answer this problem? actually i don't know what solution to use.

this is the situation: a spaceship is on a straight line path between the earth and its moon. at what distance from earth is the net gravitational force of the spaceship is zero?

it will really help a lot. thanks for your concern.

2007-10-11 00:03:52 · 3 answers · asked by glacylyn e 1

i have capsule filled with oil ( density 0.8 ) with atm.temp. initial pr. at the time of filling 1bar.final pr? when volume difference considered as 0.02684 cc & final temp of oil be supposed to increase by 1ºC..

2007-10-10 23:55:22 · 1 answers · asked by shailesh s 1

Suppose you are running carying a mirror in frint of you.Now if your velocity keeps increasing and slowly approaches the velocity of light then how will your image change?

2007-10-10 23:27:41 · 7 answers · asked by S V R 1

Are they conditions (or have there been conditions) when a mass which orbits a primary (similar to an asteroid belt) coalesces into a solid ring around that primary? I would like to assume that this mass has a radius similar to our distance form the sun and that the ring might posses enough gravity to hold an atmosphere. Under what conditions could this form?

2007-10-10 22:48:55 · 3 answers · asked by Gaspode the wonder dog 4

Jack be nimble, Jack be quick, Jack jumped over the candlestick with a velocity of 5.0 m/s at an angle of 30.0 degrees to the horizontal. Did Jack burn his feet on the 0.25 m high candle?

Here's the problem... I think I need to know the time of the jump to figure out if he would have made it over or not, but I can't figure out how to do it...
Can someone please explain to me how to do this?
Thanks in advance.

2007-10-10 21:42:00 · 7 answers · asked by Anonymous

2007-10-10 19:50:36 · 6 answers · asked by Mercury 2010 7

2007-10-10 19:37:49 · 15 answers · asked by Anonymous

And why why ammeters are always connected in series!

2007-10-10 19:37:16 · 9 answers · asked by Andy mark 1

And how do you prove it without using a specific example.

2007-10-10 19:11:52 · 8 answers · asked by curiousgeorge 2

An ice skater of mass m is given a shove on a frozen pond. After the shove she has a speed of v_1 = 2 m/s. Assume that the only horizontal force that acts on her is a slight frictional force between the blades of the skates and the ice.

Use the net work-kinetic energy theorem to find the distance the skater moves before coming to rest. Assume that the coefficient of kinetic friction between the blades of the skates and the ice is u^kin = 0.12. Explain your work. Thanks! :)

2007-10-10 18:58:51 · 1 answers · asked by Anonymous

a rocket is fired vertically from a well. A catapult gives it an initial speed of 80m/s at ground level. its engine then fires and it accelerates upward at 4 m/s^2 until it reaches an altitude of 1000 m. at that point its engines fail and the rocket goes into freefall with an acceleration of -9.8 m/s^2.

How long is the rocket in motion above the ground

What is its max altitude

what is its velocity just before it collides with the earth

(You will need to consider the motion while the engine is operating separately from the free fall)

Please help

2007-10-10 18:52:09 · 4 answers · asked by tuerving 2

okay a girl watches a train pass by. the cars of each train is 8.6 m long. the first one passes her in 1.5 s and the second in 1.1 s. Find the constant acceleration. Please explain how you approached this problem?

2007-10-10 18:46:47 · 3 answers · asked by tuerving 2

the nature of the sound and its loudness is different when we tear a wet paper.

2007-10-10 17:55:17 · 7 answers · asked by raj 2

The tires on a new compact car have a diameter of 2.0 ft and are warranted for 58,000 miles.

Determine the angle (in radians) through which one of these tires will rotate during the warranty period.
?rad

How many revolutions of the tire are equivalent to your answer in (a)?
?rev

2007-10-10 17:49:43 · 1 answers · asked by Ashley S 1

A 7.0 kg block is pushed 3.0 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of = 30° with the horizontal, as shown in Figure http://www.webassign.net/sf/p5_70.gif . If the coefficient of kinetic friction between block and wall is 0.30, determine the work done by each of the following.

Find
a. the force F

b. gravity

c. the normal force between block and wall

d. By how much does the gravitational potential energy increase during the block's motion?

2007-10-10 17:39:52 · 1 answers · asked by Anonymous

A 223 g particle is released from rest at point A on the inside of a smooth hemispherical bowl of radius R = 27.0 cm http://www.webassign.net/sercp/p5-65.gif

Find
a. its gravitational potential energy at A relative to B

b. its kinetic energy at B

c. its speed at B

d. its potential energy at C relative to B

e. its kinetic energy at C

2007-10-10 17:36:19 · 2 answers · asked by Anonymous