Physics - November 2007

2007-11-25 13:48:49 · 6 answers · asked by kaynaptx 1

A man weighing 750N and a woman weighing 410N have the same momentum. What is the ratio of the man's kinetic energy Km to that of the woman Kw ?

2007-11-25 13:42:35 · 2 answers · asked by coca 1

Does your body directly sense a gravitational field? Compare to what you would feel in free fall.

This is a question from chapter 6 of a physics textbook, please help if you can! Many thanks!

2007-11-25 13:21:30 · 3 answers · asked by Kiwikahuna 2

A person bounces up and down on a trampoline, while always staying in contact with it. The motion is simple harmonic motion, and it takes 1.90s to complete one cycle. The height of each bounce above the equilibrium is 45 cm. Determine the amplitude and the angular frequency of the motion. What is the maximum speed attained by the person?

Please tell the equation used and describe what was done in detail.....Thanks

2007-11-25 13:18:24 · 3 answers · asked by Jamgirl108 1

2007-11-25 13:12:42 · 1 answers · asked by Lisaaa 1

I have a question that asks: What is the mass of a block of wood that weighs 6.0 Newtons?

Is there a formula for this, like mass x grams or some other?

2007-11-25 12:36:54 · 4 answers · asked by platypus 2

As you can see Ladies and Gents our kids have crάpped this category with drab and boring questions, the bulk being ungrateful to their answerers; I hope my question would entertain you a bit;

So why Chinese roofs are crooked? What can you say about roofs of other cultures? How could you explain this variety?
Since this is physics category, analysis, speculations, and formulas are welcome; do not hurry, the first does not mean the best! I’ve never seen this question anywhere before not saying of the answer;

2007-11-25 12:33:01 · 2 answers · asked by Anonymous

Gayle runs at a speed of 3.45 m/s and dives on a sled, initially at rest on the top of a frictionless snow covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. What is their speed at the bottom of the hill if the total vertical drop is 18.5 m? Gayle's mass is 50.0 kg, the sled has a mass of 5.00 kg and her brother has a mass of 30.0 kg.
m/s

2007-11-25 12:22:43 · 1 answers · asked by Anonymous

a 10 kg object is being pulled to the left at a constant speed of 2.5 m/s. F norm is 80 and there is a 30 degree angle. find the applied force, F grav force, "mu" force, and the friction force.

Please help!! I know its a lot of work, but im soo stuck!!

2007-11-25 12:16:16 · 1 answers · asked by Fuzzyglasses 3

A box weighing 100 newtons is pushed up an inclined plane that is 5 meters long. It takes a force of 75 newtons to push it to the top, which has a height of 3 meters.

How do i find the Percent Efficiency in this problem?? PLEASE HELP!!

2007-11-25 12:09:10 · 2 answers · asked by Anonymous

2007-11-25 11:59:21 · 2 answers · asked by Anonymous

The radius of curvature of a loop-to-loop roller coaster is 12 m. At the top of the loop, the force that the seat exerts on a passenger of mass m is 0.4mg. Find the speed of the roller coaster at the top of the loop. Answer: v = 12.83 m/s.

Please provide step by step instructions on how you solve this.

2007-11-25 11:23:00 · 1 answers · asked by ? 2

There are various ways in which a person could "travel into the future" in a limited sense: the person could set things up so that in a small amount of their own subjective time, a large amount of subjective time has passed for other people on Earth. For example, an observer might take a trip away from the Earth and back at relativistic velocities, with the trip only lasting a few years according to the observer's own clocks, and return to find that thousands of years had passed on Earth. It should be noted, though, that according to relativity there is no objective answer to the question of how much time "really" passed during the trip; it would be equally valid to say that the trip had lasted only a few years or that the trip had lasted thousands of years, depending on your choice of reference frame.

2007-11-25 11:15:35 · 8 answers · asked by Anonymous

2007-11-25 10:55:10 · 3 answers · asked by Anonymous

The bottom of a flat-bottom aluminum boat has an area = 4 m2 and the mass of the boat is 65 kg. If two fishermen and their fishing gear with total mass of 375 kg are placed in the boat, how much lower will the boat ride in water? (water density = 1000 kg/m3)

2007-11-25 10:54:44 · 2 answers · asked by Zeezee 3

We have a wire of 1 m and we bend it in a shape of S. When I say "in shape of S" I mean by sides being verticals and horizontals not curvey sides.

Okay so Four sides of the shape of S are 22.22 cm and one side is 11.11 cm, making it 1 m. So how do I find the center of mass:

1) by hanging the configuration, S, from a string or hook.
2) by measuring the configuration, S, and calculating the Center of mass with formulas.

And one more thing the sides could be on any side it doesnt matter.

Thanks in advance

2007-11-25 10:28:59 · 1 answers · asked by Need help plz!!! 1

A .04 kg bullet is fired into a .40 kg block of wood at rest. After impact the block slides 10 m before coming to rest. If coefficient of friction is .3, find the speed of the bullet before impact.

2007-11-25 10:17:29 · 1 answers · asked by Anonymous

An object has a mass of 40 kg and a velocity of 10m/s. It collides with two masses (each mass 40 kg) attached to each other and moving with a velocity of 2 m/s. All three objects are stuck together after collision. What is the velocity of the three masses after collision?

2007-11-25 09:57:53 · 1 answers · asked by Anonymous

An amusement park ride consists of a rotating vertical cylinder with rough canvas walls. The floor is initial about halfway up the cylinder wall. After the rider has entered and the cylinder is rotating sufficiently fast, the floor is dropped down, yet the rider does not slide down. The rider has a mass of 50 kg, the radius of the cylinder is 5m, the angular velocity of the cylinder when rotating is 2 radians per second, and the coefficent of static friction between the rider and the wall is .6

a. calculate the centripetal force on the rider when the cylinder is rotating and state what provides that force

b. Calculate the upward force that keeps the rider from falling when the floor is dropped down and state what provides that force

c. at the same rotational speed, would a rider of twice the mass slide down the wall? explain

2007-11-25 09:26:49 · 1 answers · asked by icnthnkvasnjr 1

here is the question -

A block of mass 15 kg stars from rest and slides a distance of 6 m down an inclined plane making an angle of 40 degrees with the horizontal. The coefficient of sliding friction between block and plane is 0.4.
The acceleration of gravity is 9.8 m/s^2.

a. What is the net force on the block along the incline? Answer in units of N.

b. What is the speed of the block after sliding 6 m? Answer in units of m/s.

c. What would be its speed if friction were negligible? Answer in units of m/s.

Your HELP is much APRRECIATED

THANK YOU

2007-11-25 09:14:03 · 2 answers · asked by mimi j 1

atom
true or false

2007-11-25 09:13:11 · 2 answers · asked by Anonymous

Hello I need help on the following question part c) I need to see if I am doing it correctly!

http://www.collegeboard.com/prod_downloads/ap/students/physics/physics_b_frq_02.pdf

For part c where it says to calculate the density of the liquid. To determine the density one needs to find the difference in vertical distance that the mass is not travelling due to the opposing buoyance force.

Does that mean the vertical distance from the object to the top of the surface?

Anyhow the following formula was shown to me :

k x delta h= mass of liquid x gravity

k x delta h = density of liquid x volume of mass x gravity

density of liquid = k x delta h / (volume off mass x gravity)

is this correct?

Thank you!!

2007-11-25 08:58:37 · 2 answers · asked by Anonymous

2007-11-25 08:32:44 · 4 answers · asked by CrazyCatGirl 2

A 1.6kg ball is attached to the end of a 0.40. string to form a pendulum. This pendulum is released from rest with the string horizontal. At the lowest point of its swing, when it is moving horizontally, the ball collides with a 0.80kg block initially at rest on a horizontal frictionless surface. The speed of the block just after the collision is 3.0m/s. What is the speed of the ball just after the collision?

2007-11-25 08:17:20 · 1 answers · asked by Anonymous

1) An aircraft enters a 75° horizontal turn at 210 kmhr and exits at 170 kmhr. the turn takes 2.3s. calculate:

i) the change in velocity
ii) the average acceleration

2) A fly sits on the edge of a 175mm diameter 45 r.p.m vinyl record. what acceleration does it experience (magnitude and direction)? Confused, it flies to the edge of a 350mm diameter 33r.p.m disk. Is this less stressful? It tires and lets go without flying. Sketch its subsequent trajectory and calculate its speed.

2007-11-25 08:16:52 · 1 answers · asked by marc e 1

The following is a link to the diagram containing the problem:
http://i7.photobucket.com/albums/y281/cowmoocher/IMG.jpg

Thanks in advance :}

2007-11-25 06:59:11 · 1 answers · asked by kat 2

A simple pendulum, 2.0m in length, is released with a push when the support string is at an angle of 25° from vertical. if the intial speed of the suspensed mass is 1.2 m/s when at the release point, what is its speed at the bottom of the swing?

2007-11-25 06:58:02 · 1 answers · asked by Afolly babe 1

2007-11-25 06:55:23 · 14 answers · asked by Anonymous

dragsters often set their tires on fire to soften the rubber and increase the coefficient of friction to nearly 5.0. What role does friction play in accelerating the dragster?

2007-11-25 06:48:29 · 8 answers · asked by Aitu4 3

A shiny new sports car sits in a parking lot of a car dealership. Above is a cargo plane, flying horizontally at 48 m/s. At the exact moment the plane is 130 m directly above the car, a heavy crate accidentally falls from its cargo doors. Relative to the car, where will the crate hit?

2007-11-25 06:43:28 · 2 answers · asked by Anonymous