Physics - November 2006

I believe it is b, just wanted to double check.

A flatbed truck is carrying a 20.0-kg crate along a level road. The coefficient of static friction between the crate and the bed is 0.400. What is the maximum acceleration that the truck can have if the crate is to stay in place?
a. 3.92 m/s squared.
b. 8.00 m/s squared.
c. 78.5 m/s squared.
d. 196 m/s squared.

2006-11-13 11:48:57 · 1 answers · asked by Banana28 1

L1 +L2, with L1 = 20cm and L2 = 80cm. The rod is held horixontally on the fulcrum and then released. What are the magintudes of the initial acceleratoins of (a) particle 1 and (b) particle 2?

2006-11-13 11:40:23 · 2 answers · asked by gods1princesschanel 1

and longitude 102degres E; the fire ball thus created was the bightest flash seen by anyone before nuclear weapons. The Tunguska Event, which according to one chance witness "convered and enormous part of the sky," was probably the explosion of a stony asteroid about 140m wide. (a) Considering only Earth's rotation, determine how much later the asteroid would hav had to arrive to put the explosion above Helsinki at longitude 25degrees E. This would have obliterated the city. (b) If the asteroid had, instead, been a metallic asteroid, it could have reached Earth's surface. How much later would such an asteroid have had to arrive to put the impact in the Atlantic Ocean at longitude 20degrees W?

2006-11-13 11:34:49 · 3 answers · asked by gods1princesschanel 1

The pull tab was a major advance in the engineering desigan of beverage containers. The tab pivots on a central bolt in the can's top. When you pull upward on one end of the tab, the other end presses downward on a portion of the can's top that has been scored. If you pull upward with a 10N force, approximately what is the magnitude of the force applied to the scored section?

2006-11-13 11:24:06 · 1 answers · asked by gods1princesschanel 1

2006-11-13 10:41:27 · 4 answers · asked by Anonymous

2006-11-13 10:21:17 · 7 answers · asked by Anonymous

2006-11-13 09:54:19 · 12 answers · asked by craftsman 1

1. A 900-N crate rests on the floor. How much work is required to move it at constant speed (a) 4.0 m along the floor against a friction force of 180 N, and (b) 4.0 m vertically?


2. A car does 7.0 x 10^4 J of work in traveling 2.8 km at constant speed. What was the average force of friction (from all sources) acting on the car?

3. A hammerhead with a mass of 2.0 kg is allowed to fall onto a nail from a height of 0.50 m . What is the maximum amount of work it could do on the nail? Why do people not just "let it fall" but add their own force to the hammer as is falls?

4. In pedaling a bicycle, a particular cyclist exerts a downward force of 90 N during each stroke. If the diameter of the circle traced by each pedial is 36 cm, calculate how much work is done in each stroke.


Please help me do and understand these problems.. Any help is appreciated. Also, show your work so that I can understand what you are doing. Thanks a whole bunch!

2006-11-13 09:53:47 · 5 answers · asked by hdwong58 3

2006-11-13 09:31:45 · 1 answers · asked by sabrina 3

I drop a cork into a tube of water and, of course, it floats. Now I put the tube in a centrifuge and spin it - fast. What happens to the cork ?

2006-11-13 09:27:44 · 2 answers · asked by black sheep 2

2006-11-13 09:14:41 · 2 answers · asked by C. 2

The acceleration of gravity on the moon is 0.166 times that on earth, and the moon's radius is 0.273 RE. What is the escape speed for a rocket leaving the moon in units of km/s?

2006-11-13 09:14:36 · 1 answers · asked by Dee 4

I believe it is a. Any suggestions?
A ball is thrown up into the air. Ignore air resistance. When it is rising and reaches half of its maximum height, the net force acting on it is:

a. Equal to its weight.
b. Greater than its weight.
c. Less than its weight, but not zero N.
d. Zero N.

2006-11-13 09:09:52 · 6 answers · asked by shaft0208 1

I believe it is a. any thoughts?

An object of weight W is in free-fall close to the surface of Earth. What is the force that the object exerts on Earth?

a. A force greater than W.
b. A force less than W.
c. A force equal to W.
d. No force at all.

2006-11-13 09:06:51 · 4 answers · asked by shaft0208 1

hello, how r u guys?? oh plz i need help in a physics question i really tried alot and alot to do it but it didn't work with me. here is the question:
The mass of a full bottle of cooking oil is 1.3 kg.
when excatly half of the oil has been used, the mass of the bottle plus the remaining oil is 0.9 kg.
what is the mass of the bottle?
plz show ur work .. i really need help:(
thanx

2006-11-13 08:49:28 · 2 answers · asked by Anonymous

2006-11-13 08:41:15 · 3 answers · asked by Anonymous

I was just curious, thanks! I always wondered how you get an electron up to light speed using mechanical devices :P.

2006-11-13 08:25:16 · 3 answers · asked by Anonymous

what type of inventions did einstein invent? are they still used now

2006-11-13 08:19:48 · 3 answers · asked by kool j 1

I am interested in issues directly related to the oil and gas exploration and production. Of course, the first task is to identify which problems need to be solved. I will be more than happy if I get specific answers about issues that affect the oil business and that are yet to be solved.

2006-11-13 08:15:05 · 1 answers · asked by imager 1

From my knowledge of physics I chose b as my answer. Any thoughts? Thanks!

When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that:

a. The acceleration is equal to g.
b. The force of air resistance is equal to zero N.
c. The effect of gravity has died down.
d. The force of air resistance is equal to the weight of the parachutist.

2006-11-13 08:10:07 · 3 answers · asked by shaft0208 1

I need to know what is the meaning of force how it works and what it measures in. Also what are the definitions of dynamic and static friction and how is this realted to force. e.g how much force do u need to put in something with X amount of friction. The teacher said something about dynamic friction minus static friction but i did not underdstand? plzz helpp

2006-11-13 08:09:56 · 2 answers · asked by Anonymous

I believe the answer is d since gravity doesn't change. But I just wanted to be sure. Thanks!

A hockey puck slides off the edge of a table with an initial velocity of 20 m/s. The height of the table above the ground is 2.0 m. What is the acceleration of the ball right after it leaves the table?
a. 20 m/s to power of (exponent).
b. 4.9 m/s to power of (exponent).
c. 19.6 m/s to power of (exponent).
d. 9.8 m/s to power of (exponent).

2006-11-13 07:58:21 · 4 answers · asked by shaft0208 1

2006-11-13 07:41:41 · 4 answers · asked by Anonymous

Any physics majors out there? Can you answer this question for me? Is there any way that two 18-wheelers, driving either side-by-side or behind one another can create a vacuum that is powerful enough to pull a regular sized automobile along with them?

2006-11-13 07:38:04 · 1 answers · asked by professionalfemale01 3

If Saturn has a mass of 95.2 times that of the earth and a radius 9.47 times that of the earth, what is the escape speed for objects on the surface of Saturn in km/s?

2006-11-13 07:19:41 · 1 answers · asked by Dee 4

a. 30 degrees above the horizontal.
b. 45 degrees above the horizontal.
c. 60 degrees above the horizontal.
d. 90 degrees above the horizontal.

Please explain, thanks!

2006-11-13 07:19:31 · 3 answers · asked by SMS 1

A device for training astronauts is designed to rotate the trainee in a horizontal circle of radius 11.5 m. If the force felt by the trainee is 7.18 times her own weight, how fast is she rotating?

Now, express your answer in revolutions per second.

How would you solve this problem?

2006-11-13 07:12:54 · 1 answers · asked by Andy H 1

in your own words... no definitions plz..

2006-11-13 07:08:32 · 5 answers · asked by Anonymous

2006-11-13 05:58:51 · 4 answers · asked by Amanuel Z 1

According to Newton's Second Law of Motion, the acceleration 'A' produced by a constant force varies inversely with the mass 'M' of the object to which the force is applied. A constant force acting upon an object with mass 2 kg produces an acceleration of 16 m/s2. The acceleration of another object produced by the same force is 8 m/s2. What is the mass of this object?

2006-11-13 05:49:23 · 4 answers · asked by pirsimone 1