Physics - October 2007

2007-10-18 19:54:32 · 2 answers · asked by ASHWINI neils bohr 1

2007-10-18 19:42:03 · 4 answers · asked by John W 1

A child of mass 40 kg is sitting on a horizontal seesaw at a distance of 4 m from the supporting axis. What is the magnitude of the torque about the axis due to the weight of the child

2007-10-18 19:24:41 · 2 answers · asked by Anonymous

A hockey puck moving along the +x axis at 0.6 m/s collides into another puck that is at rest. The pucks have equal mass. The first puck is deflected 34 below the +x axis and moves off at 0.46 m/s. Find the speed and direction of the second puck after the collision. [please use positive for counterclockwise (above the +x axis) and negative for clockwise (below the +x axis)]:

2007-10-18 19:18:32 · 3 answers · asked by Anonymous

Two LORAN stations are placed 150 miles apart along a straight shore and act as the foci of a hyperbola. A ship records a time difference of 0.0005 second between the LORAN signals. Set up a rectangular coordinate system to determine where the ship would reach shore if it were to follow the hyperbola corresponding to this time difference. The speed of radio-signals is 186000 miles per second.
What is the equation of the hyperbola?

SHOW ME HOW TO SET IT UP PLEASE

2007-10-18 19:09:23 · 1 answers · asked by Anonymous

Would speeding be a good way to lose weight?

2007-10-18 18:55:16 · 3 answers · asked by Anonymous

The area under the force vs. distance graph is the work done to stretch the spring. How does the work depend on the amount of stretch?

2007-10-18 18:06:42 · 4 answers · asked by Natiphy2007 1

I am doing a research papaer at the last minute and its very late so my brain isn't working right. There is a tool (and its name is at the tip of my tongue) the electrically measures the mass of an object. Is it an electric scale? Its a tool (kinda like a scale) were you place something on it and it gives you the mass. I know its an electric ____ and I'm going to feel like a complete idiot when I finally find what it is, but oh well. Help? lol

2007-10-18 18:01:34 · 5 answers · asked by Kayt 2

consider a ball in air as it travels through a closed system. the ball loses both kinetic and gravitational potential energy so how can this be reconciled with conservation of energy? where does the energy go?

2007-10-18 18:01:27 · 2 answers · asked by robinf1988 1

strikes the ground. Answer in units of m/s.

b)How much time does a passerby on the sidewalk below have to move out of the way before the flowerpot hits the ground? Answer in units of m/s.

I'm having a hard time figuring out what formulas to use and how to plug everything into the formula so any help would be greatly appreciated.

2007-10-18 17:50:44 · 4 answers · asked by americasnextopfashiondesigner 2

can you define buoyancy in simple words for me? why does a ball of clay sink, while a boat shape floats?

2007-10-18 17:49:34 · 5 answers · asked by Sarah S 3

I know that we actually cant come any were near the speed of light right now or any time soon.

But Light is measured as traveling 186,282.397 miles per second,

Now I'm no scientist, but I know that that is Bitchingly fast...

But I can't help but thing, If light can be measured like that, dosent that fundamentally mean that there is some way to go faster then that.

If light can go from earth to the moon in 1.2 seconds, how can we say that can't be broken, couldent there be something out there that can go from the earth to the moon in 1.1 seconds.

Now Im not talking about aliens or star trek or anything, but if civilization lasts long enough, and we actually start to get smarter (Unlikely as that would be) and our technology continues to grow, couldn't the human race, or some race in the stars if there is one, somehow find a way to travel faster then light speed.

Now I'm not gonna pretend to know dittily about science or physics.

But my common sense is telling me that if something has a defined speed, there has to be someway to go faster then it as long as that speed has a constant measurement.

2007-10-18 17:42:44 · 17 answers · asked by Anonymous

Pluto's diameter is approximately 2370 km, and the diameter of its satellite Charon is 1250 km. Although the distance varies, they are often about 1.95×104 km apart, center-to-center.
Assuming that both Pluto and Charon have the same composition and hence the same average density, find the location of the center of mass of this system relative to the center of Pluto.

2007-10-18 17:23:12 · 4 answers · asked by Madiyar T 1

2007-10-18 17:14:02 · 5 answers · asked by Anonymous

A sailboat is traveling in the direction of 40 degress west of north at a speed of 3 m/s.

resolve the velocity vector into components. Compute the velocity componenets and describe their directions.

2007-10-18 16:53:48 · 4 answers · asked by lub1210 1

A bicycle has wheels of radius 0.24 m. Each wheel has a rotational inertia of 0.087 kg* m2 about its axle. The total mass of the bicycle including the wheels and the rider is 74 kg. When coasting at constant speed, what fraction of the total kinetic energy of the bicycle (including rider) is the rotational kinetic energy of the wheels?

I'm just really confused about this question

any help would be greatly appreciated

2007-10-18 16:42:50 · 4 answers · asked by Anonymous

A particle travels between two parallel vertical walls separated by 11 m. It moves to ward the opposing wall at a constant rate of 6.3m/s. It hits the opposite wall at the same height and the acceleration of gravity is 9.8m/s^2. I need to find what its speed will be when it hits the opposing wall. I thought it was 6.3m/s but it's not.

2007-10-18 16:06:32 · 1 answers · asked by Anonymous

Water flows over a section of Niagara Falls at a rate of 2.3e6 kg/s and falls 70 m. The acceleration of gravity is 9.8 m/s^2. What is the power wasted by the waterfall? Answer in units of W.

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Given: 1 hp = 746 W and 1 m/s = 2:237 mi/h. When an automobile moves with constant velocity, the power developed in a certain engine is 114 hp.
What total frictional force acts on the car at v = 74.9 mi/h? Answer in units of N.

2007-10-18 15:36:52 · 1 answers · asked by Captain Jack is Back 1

A 2:35 kg block is pushed 1.57 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 67:5 degree with the horizontal. The acceleration of gravity is 9.8 m/s2. If the coefficient of kinetic friction between the block and wall is 0:678, and the work done
by F. Answer in units of J.

2007-10-18 15:07:28 · 2 answers · asked by Captain Jack is Back 1

a trapeze artist weighs 8.00 * 10^2 . The artist is momentarily held to one side of a swing by a partner so that both of the swing ropes are at an angle of 30.0 degrees with the vertical.In such a condition of static equilibrium, what is the horizontal force being applied by the partner?

2007-10-18 14:58:17 · 1 answers · asked by juliamr4 1

The instruments attached to a weather balloon have a mass of 5.5kg. The balloon is released and exerts an upward force of 97.7 N on the instruments. Acceleration of gravity is 9.8 m/s^2
What is the acceleration of the balloon and the instruments? Answer in units of m/s^2.
Also after the balloon has accelerated for 10.5 s, the instruments are released. What is the velocity of the instruments at the moment of their release.? Answer in m/s.
Assume: The upward direction is positive. What net force acts on the instruments after their release? Answer in N.
How long after their release does the direction of their velocity first become downward(negative)? Answer in units of s.

Pleaseeeee explain, i am desperate i spent 10 hours on 5 problems and i haven't solved not one! please help

2007-10-18 14:55:11 · 2 answers · asked by Anonymous

A bicycle has wheels of radius 0.29 m. Each wheel has a rotational inertia of 0.078 kg* m2 about its axle. The total mass of the bicycle including the wheels and the rider is 74 kg. When coasting at constant speed, what fraction of the total kinetic energy of the bicycle (including rider) is the rotational kinetic energy of the wheels?

I just don't know what they are asking for?

2007-10-18 14:52:29 · 1 answers · asked by Anonymous

the object's temperature is 500k. Moving at 3m/sec for 4.5 m. what is the total heat lost and what is the final temperature?

2007-10-18 14:52:00 · 1 answers · asked by haohao 1

2007-10-18 14:48:49 · 1 answers · asked by Anonymous

to the ground is ??????

2007-10-18 14:36:16 · 1 answers · asked by Anonymous

I've been working on this problem, and I can't seem to get it. Please, can someone help me out...

Two particles, of masses m and 4m , are moving toward each other along the x-axis with the same initial speeds of 6.53 m/s. Mass m is traveling to the left, and mass 4m is traveling to the right. They undergo a head-on elastic collision, and each rebounds along the same line as it approached.

I need to find the final speed of the heavier particle.
Any help would be very much appreciated, Thanks in advance.

2007-10-18 14:20:32 · 2 answers · asked by Anonymous

A spring with a force constant of 3.1 104 N/m is initially at its equilibrium length.
(a) How much work must you do to stretch the spring 0.053 m?

(b) How much work must you do to compress it 0.053 m?

2007-10-18 14:09:47 · 2 answers · asked by Anonymous

A block with mass m = 12.9 kg slides down an inclined plane of slope angle 22.6 ° with a constant velocity. It is then projected up the same plane with an initial speed 4.80 m/s. How far up the incline will the block move before coming to rest?

2007-10-18 13:52:06 · 2 answers · asked by Anonymous

Harry falls out of a helicopter traveling 100 m/s. He plunges into a swimming pool 2 seconds later. assuming no air resistance what was the horizontal distance between harry and the swimming pool when he fell out of the helicopter?

A girl throws a slingshot pellet directly at a tarfet that is far enough away to take one hald second to reach. How far below the target does the pellet land and how high should she aim?

the simpler the answer but most descriptive the better
Please help =]

2007-10-18 13:49:36 · 1 answers · asked by njswimchick99 1

answer in units of seconds

2007-10-18 13:44:21 · 2 answers · asked by Amos G 2