Physics - October 2007

a) a mercury vapor streetlight
b) an incandescent (tungsten filament) streetlight
c) a star like the sun

how do you know which spectrum it is?

2007-10-31 21:13:14 · 2 answers · asked by Anonymous

held a mirror in front of u, what would you see?

2007-10-31 19:56:07 · 8 answers · asked by Anonymous

And FREAKINGLY FAST when taking exams or craming for deadlines?

2007-10-31 19:35:55 · 10 answers · asked by ? 5

Does the distance between maxima increase or decrease or stay the same when the slit separation is increased? when the slit width is increased? what about minima?

2007-10-31 19:01:23 · 1 answers · asked by Anonymous

Are there any leads? will we see it in our lifetime?

2007-10-31 18:59:00 · 7 answers · asked by Anonymous

2007-10-31 18:39:07 · 13 answers · asked by e_rack 2

You have a container full of ice blocks in the fire, and before the ice blocks melt completely, you get the container out of the fire. Would you grab the recipient with your hands? Yes/No, why? I need well-founded physics-related answers.

I would do it.

2007-10-31 18:03:07 · 1 answers · asked by ddeity_inc 3

2007-10-31 17:32:48 · 4 answers · asked by mk 2

I know the answers... please help me work them out. Thanks!

The steel I-beam in the drawing has a weight of 8.00 kN and is being lifted at a constant velocity. What is the tension in each cable attached to its ends? There is a triangle drawn with 70 degree angles on both the left and right sides.

2007-10-31 17:15:45 · 1 answers · asked by PinkyTrauma 2

Once again... I have answers just need help figuring out how to work them out. This is almost a daily occurance for me.. so if you like physics questions I'm your girl!

. A bowling ball (m = 7.2 kg, r = 0.11 m) and a billiard ball (m = 0.38 kg, r = 0.028 m) may each be treated as uniform spheres. What is the magnitude of the maximum gravitational force that each can exert on the other?

2007-10-31 17:14:06 · 1 answers · asked by PinkyTrauma 2

Once again, I know the answers just don't know how they were gotten. So please help if you can!

At what angle should a curve of radius 150 m be banked, so cars can travel safely at 25 m/s without relying on friction?

2007-10-31 17:07:46 · 1 answers · asked by PinkyTrauma 2

I need help working these out. I have all the answers but it doesn't help when I don't know how they got them.

A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to twice her weight as she goes through the dip. If r = 20.0 m, how fast is the roller coaster traveling at the bottom of the dip?

2007-10-31 17:05:53 · 1 answers · asked by PinkyTrauma 2

2007-10-31 17:02:54 · 2 answers · asked by seph 2

I need help.

these sentances will have to do with one of newtons laws of motion, can u help me identify each?

1.Earth constantly revolves around the sun

2.you kick a soccer ball

3.you drop a book

4.a jet plane takes off.

i think u might have ti use some twice

2007-10-31 16:19:52 · 1 answers · asked by Steven 2

The skateboarder in the drawing starts down the left side of the ramp with an initial speed of 7.96 m/s. If non-conservative forces, such as kinetic friction and air resistance, are negligible, what would be the height h of the highest point reached by the skateboarder on the right side of the ramp?

2007-10-31 16:16:10 · 2 answers · asked by Xiaolin L 2

Hey, I know this is REALLY stupid but i want to know if telekinesis is real. A lot of websites say it is but i want to know for sure. Could you tell me if its real? If you know could you tell me HOW you know?

2007-10-31 15:51:21 · 2 answers · asked by David S 1

One mans lives at an altitude of 3000km for a year and another at sea level. What is the difference of time how do you calculate it?

2007-10-31 15:39:18 · 5 answers · asked by Anonymous

The bag is tied to a thwart and suspended in the water underneath the canoe. The canoe:

(a) floats deeper in the water
(b) floats higher in the water
(c) floats at the same level (draft)
(d) sinks

This is an actual exam question from a course on ship structure and stability. Anyone want to take a shot at it?

A little more info: a thwart is a cross-beam, which in a canoe would be used as a seat. Also, I think the "net bag" suggests that water will penetrate the bag, so there won't be any buoyancy contributed from the bag itself.

2007-10-31 14:22:27 · 6 answers · asked by Stephen S 1

If you could, theoretically suspend a particle of matter at the point it would be an instant before entering the singularity of a black hole, what would its gravitational potential energy be?

2007-10-31 14:14:39 · 1 answers · asked by Outlawed Spirit 2

2007-10-31 14:13:30 · 1 answers · asked by Anonymous

a 873kg dragster, starting from rest, attains a speed of 26.3 m/s in .59s

A.) find the avergae acceleration of the dragster during this time interval
B.) what is the magnitude of the average net force on the dragster during this time?
C.) assume that the driver has a mass of 68 kg. what horizontal force does the seat exert on the driver?

2007-10-31 14:13:16 · 2 answers · asked by kiwi 1

A person is making homemade ice cream. She exerts a force of magnitude 17 N on the free end of the crank handle, and this end moves in a circular path of radius 0.33 m. The force is always applied parallel to the motion of the handle. If the handle is turned once every 1.8 s, what is the average power being expended?

i attempted this already and it said i was wrong. my teacher hasn't taught us power yet but i guess because im in ap, he thinks we can do web assign by ourselves untaught. this is due tonight. please help me. i really have tried and came here as a last resort. i tried to do it by my self and found i really do just need help. please, explain how to do this

thank you so very much!!!!

2007-10-31 14:12:29 · 1 answers · asked by Elizabeth 3

The mass of a simple pendulum of length, L = 1.0 m is released with the string originially in a horizontal position.. (a) Calculate the speed of the mass at its lowest position. (b) what is the speed when the string makes an angle of 45 degrees with the vertical? (c) Determine the tension in the string in both poistions if the mass is .2 kg

andddd

A machine gun in automatic moe fires 20-g bullets with v(bullet) = 300 m/s at 60 bullets/s. (a) if the bullets enter a thick wooden wall, whts is the average force exerted against the wall? (b) if the bullets hit a steel walland rebound elastically, what is the average force on the wall?

2007-10-31 14:08:23 · 1 answers · asked by Anonymous

hole of area is 1.1^2 at a depth of 1m below the water surface

2007-10-31 14:03:55 · 1 answers · asked by Anonymous

Fairgoers ride a Ferris wheel with a radius of 6.00 m (Figure 4-18), the bottom of which is 1.75 m above the ground. The wheel completes one revolution every 28.0 s.

Figure 4-18


(b) If a rider accidentally drops a stuffed animal at the top of the wheel, where does it land relative to the base of the ride? (Neglect air resistance.)
m

2007-10-31 13:45:40 · 2 answers · asked by Chris B 1

A player passes a 0.6 kg basketball downcourt for a fast break. The ball leaves the player's hands with a speed of 7 m/s and slows down to 4.9 m/s at its highest point.

How high (above the release point) is the ball when it is at its maximum height?

2007-10-31 13:38:45 · 1 answers · asked by =P 6

v^2 = u^2 + 2as ?

This formula is used for what? I was looking through the book just now when I came across this formula that I have never seen before...Please help me by telling how to use this formula and when to use this formula...What's impt is that you can tell me how do you derive this formula cos I HAVE NEVER SEEN IT BEFORE? Thanks

2007-10-31 13:19:19 · 1 answers · asked by Anonymous

2007-10-31 13:14:45 · 2 answers · asked by Anonymous

A projectile is fired horizontally from a gun that is 41.0 m above flat ground, emerging from the gun with a speed of 250 m/s.
It remains in the air for 2.9 seconds.

1.) At what horizontal distance from the firing point does it strike the ground? (m)

2.) What is the magnitude of the vertical component of its velocity as it strikes the ground? (m/s)

2007-10-31 12:59:42 · 3 answers · asked by Chaz 3

two blocks, of mass m1 = 250 g and m2 = 700 g, are connected by a massless cord that is wrapped around a uniform disk of mass M = 500 g and radius R = 12.0 cm. The disk can rotate without friction about a fixed horizontal axis through its center; the cord cannot slip on the disk. The system is released from rest.

a) Find the magnitude of the acceleration of the blocks.
=.......m/s^2
(b) Find the tension T1 in the cord at the left.
=.......N
(c) Find the tension T2 in the cord at the right.
=........N

2007-10-31 12:48:59 · 1 answers · asked by Nikita 1