Physics - November 2006

I'm in desperate need of physics help. This problem is complicated.

A particle of mass 0.5-kg is shot from P, 60m above the ground at an angle of theta. The particle has an inital velocity vector V(initial) with a horizontal component of 30 m/s. The particle rises to a mazimum height of 20m above P. Using the law of conservation of energy, determine a) the vertical component of vector V(initial), b) the work done by the gravitational force on the particle during its motion from P to the ground, and c) the horizontal and vertical components of the velocity vector when the particle reaches the ground.

Please...please....sigh.

2006-11-09 14:20:11 · 3 answers · asked by andrew c 1

A 2.44 kg block is pushed 1.56 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 58.2 degrees with the horizontal. The acceleration of gravity is 9.8 m/s2. If the coefficient of kinetic friction between the block and wall is 0.65 find the work done by F.

2006-11-09 14:08:50 · 1 answers · asked by Anonymous

Why is string theory such a prevalent theory among physicists when there is absolutely no empirical evidence for it?

2006-11-09 14:07:01 · 5 answers · asked by taotemu 3

thanks i owe ya one

2006-11-09 14:04:58 · 3 answers · asked by cartergirl_denise 1

thanks

2006-11-09 14:01:03 · 6 answers · asked by cartergirl_denise 1

Just Help me in discussing the effects of mass and air resistance to "Gravitational Acceleration". Thanks

2006-11-09 13:53:15 · 4 answers · asked by Anonymous

A 1000kg car racing up a mountain road runs out of gas at a height of 35m while traveling at 24m/s. The driver shifts into neutral and coasts onward. Neglecting all frictional losses.

1.Will he clear the 65m summit?


2. His brakes fail; at what speed will he reach the bottom of whichever side of the mountain he rolls down?

2006-11-09 13:38:25 · 3 answers · asked by Shane W 1

A 400-N child is in a swing that is attached to ropes 2m long. Find the gravitational potential energy of the child-Earth system relative to the child's lowest position when a) the ropes are horizontal, b) the ropes make a 30 deg angle with the vertical, c) and the child is at the bottom of the circular arc.

So part (a) would give me 800J. I use the U=mgh equation to find gravitational potential energy. So would part (b) look anything like this?

b) U = 400(cos20)*2?

and part c like this?

c) U = 400(0) ?

i'm not understanding this...please help.

2006-11-09 13:22:28 · 2 answers · asked by andrew c 1

Not ligh bulbs, LED or fire. But the light itself, what is it and where does it come from?

2006-11-09 13:22:05 · 8 answers · asked by ? 2

O.K. here is a chance for all you genius abstract thinkers to shine. These areas of thought concern the evolution of quantum physics and its various modes of expression. This is not an easy question and I will be amazed if I get any real answers = )

2006-11-09 12:47:45 · 4 answers · asked by spicyninja23 2

Measurements on two stars indicate that Star X has a surface temperature of 5227°C and Star Y has a surface temperature of 9627°C. If both stars have the same radius, what is the ratio of the luminosity (total power output) of Star Y to the luminosity of Star X? Both stars can be considered to have an emissivity of 1.0

2006-11-09 12:36:14 · 2 answers · asked by rhondasumpter 2

I need to know how many protons & neutrons are in the nucleus of a silicon atom for a school report i'm doing.

2006-11-09 12:13:33 · 6 answers · asked by K. R. Vance 1

If change in meter is speed.
If change in speed is acceleration
If change in acceleration is ????
If change in ???? is ???????????

2006-11-09 12:10:09 · 9 answers · asked by Mr. Logic 3

angle of 15.9 deg with the horizontal. An average frictional force of 4.3 x 10^3 N impedes the car's motion so that the car's speed at the bottom of the driveway is 3.8 m/s. What is the length of the driveway? Answer in units of m.

2006-11-09 11:54:26 · 3 answers · asked by drdagher89 2

A diving board of length L = 3.00 m is supported at a point a distance 1.00 m from the end, and a diver weighing 550 N stands at the free end View Figure . The diving board is of uniform cross section and weighs 300 N.

Find the force at the support point.

Find the force at the end that is held down.

2006-11-09 11:45:12 · 3 answers · asked by darkangelwattitude 1

Why is analogue transmission used for long distance transmission?

2006-11-09 11:31:15 · 2 answers · asked by english_monster 2

2006-11-09 11:16:45 · 15 answers · asked by shorty 1

I also need help with other physics questions so if anyone is good at physics please have pity and send help! Also please send equations used with answers, so that I can learn to do it myself.

2006-11-09 11:07:04 · 6 answers · asked by mariandmommy 2

A 72.0 kg box slides down a 29 degree ramp with an acceleration of 3.5 m/s/s. The acceleration of gravity is 9.81 m/s/s. Find the coefficient of kinetic friction between the box and the ramp. How would I solve this? I'm tilting the problem so that the only part that needs to be broken into components is the Fg.

2006-11-09 11:04:05 · 5 answers · asked by Audrey M 1

A large superball and a small superball are dropped from the same initial height H. Both balls bounce backup to a height h, which is just a bit less than H. If, however, the small superball is placed immediately above the large superball and both are dropped to the ground simultaneously from height H, the small superball rebounds to a height h' > H! Explain this in terms of Conservation Laws.

Is it because the larger ball is providing the smaller one with extra "bounce"? I'm not exactly sure...thanks =)

2006-11-09 11:01:46 · 3 answers · asked by Silver 2

A crate is pulled a force ( parallel to the incline) up a rough incline. The crate has an initial speed of 1.53 m/s The crate's mass is 11 kg. The crate is pulled a distance of 7.46 m on the incline by a 150 N force. The coefficient of kinetic friction is 0.347 between the crate and the incline. The acceleration of gravity is 9.8 m/s2.

a) What is the change in kinetic energy of the crate ?
b) What is the speed of the crate after it is pulled the 7.46 m ?

2006-11-09 10:55:13 · 2 answers · asked by Anonymous

sciense question

2006-11-09 10:51:30 · 3 answers · asked by Tristen C 1

A mechanic pushes a 3253 kg car from rest to a speed of v, doing 3996 J of work in the process. During this time, the car moves 23 m.
a) Neglecting friction between the car and the road find v.
b) Find the horizontal force exerted on the car.

2006-11-09 10:49:58 · 1 answers · asked by Anonymous

A 73.3 kg bobsled is pushed along a horizontal surface by two athletes. After the bobsled is pushed a distance of 5.6 starting from rest its speed is 7.1 m/s. Find the magnituide of the net force on the bobsled. Answer in units of N.

2006-11-09 10:47:55 · 2 answers · asked by Anonymous

Typically, when the sun is setting in a clear sky, it gets redder and redder due to the refraction of light causing by thicker and thicker layers of atmosphere. When I get up in the morning and the sun is at about the same angles above the horizon, it doesn't appear red. Yellowish, maybe, but not the intense red of sunset.

Any ideas? I've seen this in many places - some polluted, some not; some by the ocean, some inland. Definite puzzlement for me.

2006-11-09 10:23:30 · 6 answers · asked by eriurana 3

2006-11-09 09:57:24 · 14 answers · asked by Anonymous

what scientist and when it was discovered

2006-11-09 09:44:04 · 4 answers · asked by angelhotface 1

2006-11-09 09:16:22 · 12 answers · asked by Anonymous

2006-11-09 08:38:54 · 5 answers · asked by Anonymous

I sometimes dream in black & white, and sometimes in colour.
I always thought that apart from geothermal energy (glowing magma and the such-like) all light could be tracked back to stars (usually the Sun)???? But when I'm dreaming I've got my eyes closed??? Is it something to do with quanta??

Many Thanks,
Jason.

2006-11-09 08:32:55 · 10 answers · asked by Anonymous