Physics - March 2007

When a golf ball is dropped to thepavement it bounces up. Is a force needed to make it bouce up? If so what exerts the force?

2007-03-01 07:55:52 · 4 answers · asked by Anonymous

2007-03-01 07:16:50 · 3 answers · asked by Gee 1

Silly question? Hmmm........... not sure. My brother told me there is a young woman in one of his college classes whos child asked her this question. I assume a pretty young child.
I like to post funny questions with my own son and see what creative and fun answers we get back. I decided to post this one for them and see what we get.

2007-03-01 07:04:00 · 4 answers · asked by Kel Kel 3

2007-03-01 06:35:47 · 9 answers · asked by Anonymous

1.) A 2.0 Kg pail rest on a scale. Water is pored into the pail from a height of 1.5 meters at a rate of 100 g/s.
a.) What is the reading on the scale in kg one minute after the pouring began?
b.) The puring stops at one minute, what is the reading on the scale afterwards?

2.) A 5.0 kg object is dropped on a spring from a height of 2 meters. If the maximum compression fo the spring is 40 cm, what is its force constant?

3.) A force of 2 Newtons is needed to push 100 g jack in the box into its box. An operation in which the spring is compressed 10 cm. What will be the maximum speed of the jack in the box when it pops out.

4.) A neutron of mass (1.67 x 10^-27)kg and speed (1.00 x 10^5)km/s collides with a stationary deuteron of mass (3.34 x 10^-27)kg. The two particles stick together. What is the speed of the composite particle?

2007-03-01 06:35:31 · 1 answers · asked by Tyler D 1

Could someone please help me with this problem?

Two wires carry currents of 3.00 A and 5.00 A in the same direction. If they are separated by a distance of 20cm:
a. Find the direction and magnitude of the magnetic field at a point midway between the wires
b. Find the magnitude and direction of the magnetic field at point P, located 20.0 cm above the wire carrying the 5.00 A current

2007-03-01 06:33:24 · 1 answers · asked by grayshore 2

Hi I just did a lab for Balmer series. For v bar one of my values was 2.67 x 10^7. I am using the equation: v bar = R (0.25 - (1/n^2)). I am supposed to solve for n but I don't think I am getting the right answer. I don't think n should be negative. Can someone explain this to me?

2007-03-01 06:21:38 · 2 answers · asked by Anonymous

I can't find this anywhere on the net. I would like to know about 2 examples of this question asked though. appreciate all the help i can get!

2007-03-01 06:05:54 · 4 answers · asked by Jimmy 3

This is a theoretical question,if a jet airplane is sitting on a giant conveyor belt that travels backwards, matching the thrust of the engine or engines will the aircraft sit there or take off ?

2007-03-01 06:05:41 · 4 answers · asked by Elmo Chan 1

Questions:

1) given that the meter stick can be read to the nearest half millimeter, what is the smallest voltage change you could measure with the potentiometer constructed?

2) give at least two changes that would make the potentiometer more sensative and explain why.

My Approach: (1) Isn't this answer 0 volts (in change of voltage) because of meter stick values? (2) I have no idea...this was a lab setup, but i have no clue what this question is asking.

Appreciate all the help i can get!

2007-03-01 06:01:23 · 1 answers · asked by Jimmy 3

If a man pushes a heavy cart with a force of 200 newtons on the cart to keep it moving at a constant velocity, what is the frictional force between the cart and the ground? Is this kinetic or static friction? please explain because i really don't understand how to do this. and i was sick this week

2007-03-01 05:52:08 · 4 answers · asked by gayle325 1

2007-03-01 05:35:07 · 2 answers · asked by westone 1

2007-03-01 05:33:58 · 5 answers · asked by westone 1

A 604N weight held by two cables. The left hand cable had tension (T2) and makes an angle of 45 degrees with the ceiling. the right hand cable had tension T1 and makes an angle of 53 degrees with the ceiling.

2007-03-01 05:20:10 · 3 answers · asked by Anonymous

Okay, this gonna sound crazy I bet. I have hazel eyes. Or what I call hazel as they change from blue, green, and brown. Often in different shades but usually darker colors. I don't know how this happens, but I'm told it has to do with my mood. Now for the impossible part.

While looking in the mirror one day, I looked up from washing my face to see my eyes were in the process of turning a medium light purple. It didn't last long, but I thought purple eyes didn't exist! I've never seen them go purple since, but I suppect they have. How is this possible? Wouldn't that mean I have eyes that can go from Brown, to green, to blue, and even purple?

2007-03-01 05:09:19 · 8 answers · asked by Maho 3

2007-03-01 05:06:59 · 2 answers · asked by Chad B 1

block 1 (mass 1.8 kg) is moving rightward at 12 m/s and block 2 (mass 4.6 kg) is moving rightward at 2.8 m/s. The surface is frictionless, and a spring with spring constant of 1160 N/m is fixed to block 2. When the blocks collide, the compression of the spring is maximum at the instant the blocks have the same velocity. Find the maximum compression.


A 5.20 g bullet moving at 620 m/s strikes a 670 g wooden block at rest on a frictionless surface. The bullet emerges, traveling in the same direction with its speed reduced to 428 m/s.
(a) What is the resulting speed of the block?
m/s
(b) What is the speed of the bullet-block center of mass?
m/s

2007-03-01 05:00:45 · 2 answers · asked by x2carlosp 2

2007-03-01 04:51:34 · 2 answers · asked by Head B 1

three uniform thin rods, each of length L = 24 cm, form an inverted U. The vertical rods each have mass of 14 g; the horizontal rod has mass of 32 g.


Where is the center of mass of the assembly?
(x, y) = ( , ) cm



a 0.165 kg cue ball bounces from the rail of a pool table. The ball's initial speed is 2.30 m/s, and the angle with the vertical = 30.0°. The bounce reverses the y component of the ball's velocity but does not alter the x component.

(b) What is the change in the ball's linear momentum in unit-vector notation? (The fact that the ball rolls is irrelevant to the question.)
____i kgm/s + ____j kgm/s

2007-03-01 04:46:01 · 2 answers · asked by x2carlosp 2

2007-03-01 04:46:00 · 3 answers · asked by abhinuke 1

2007-03-01 04:37:48 · 13 answers · asked by Anonymous

Im pretty sure it is if u can get moving at the speed of light, or near it. Can some1 please explain it a little more scientifically....I am educated, but not a genius so somewhere in the middle if u could. If it is possible does it look like we'll ever achieve it. What about going back in time? Any comments, input, answers on this topic welcome. Thanks

2007-03-01 04:28:20 · 11 answers · asked by mmmmmmm 3

Recently discovered intelligent ants mint and circulate perfect
silver coins d = 1.483 μm in diameter and h = d = 1.483 μm thick.
Such coins placed on flat level surface flip from time to time
due to Brownian motion.

What portions of time Th /Tt /Te does such coin spend in
heads / tails / edge states?


k = 1.38065 × 10e-23 J/K
ρ(Ag) = 1.049 × 10e4 kg/m³
T = 300 K
g = 9.80 m/s²

2007-03-01 04:27:21 · 4 answers · asked by Alexander 6

A driver of mass 80kg collides head-on against a huge brick wall. During the crash, the driver hits his face against the steering wheel and experts determine that his deceleration on impact was about 250m/s^2.
1) Estimate the force he sustains on impact.
2) If the car had an initial velocity of 22m/s, estimate the driver's time of impact with the steering wheel.
3) The driver suffers huge facial injuries. From a physicist's point of view, how could the use of an airbag help reduce such injuries?

2007-03-01 04:22:36 · 3 answers · asked by gianluca_azz 1

An air bubble released from a diver's breathing apparatus at a depth of 40 m with diameter 2.0. When it reaches the surface water has Diameter of 3.4.
Show volume of air bubble is approx 5.
Done!
Easy...

V=4/3 x 3.14 x 1^3
V=4.18cm^3

V=4/3 x 3.14 x 1.7^3

V=20.56

So 20.56/4.18= 4.9 = approx 5.

Q
Hence Calculate the increase in pressure experienced by the diver when descending to a depth of 40m, assuming that temperature is constant.

Oh and BTW: Atmospheric pressure= 101kPa.

Not my homework!

2007-03-01 04:20:11 · 3 answers · asked by Miss LaStrange 5

2007-03-01 03:50:50 · 2 answers · asked by webogirl 2

wot would light come out as if instead of a glass lightbulb the glas were replaced with diamond, wouldn't all the light be refracted.
Cant really picture it. how bout u

2007-03-01 03:46:49 · 4 answers · asked by Anonymous

A rubber ball with a mass of .210 kg is thrown exactly horizontally form a height of 2meters with an initial spedd of v=13m/s. when it strikes the ground, it bounces off at the same angle it made when it landed. During the bounce, it loses 20% of it's kinetic energy to dissipative forces. How high does it go after bouncing?


I know the answer is 1.6 but I'm still confused as to why....my teacher printed out answers and showed how he did the problem but his way was rather confusing and I would just like to see it done from another perspective if possible...thanks

2007-03-01 03:46:02 · 3 answers · asked by Kimmy D 1

Can someone explain to me in laymens terms what Einstein's general theory of relativity means and how it applies to the world around us. Also explain E=MC2.

Thanks

2007-03-01 03:37:29 · 7 answers · asked by t_zoid52 2

What I mean is, did he create a spaceship/plane that doesn't create actual lift. But it turns off gravity around it when not even in space?
http://news.yahoo.com/s/ap/20070301/ap_on_sc/stephen_hawking

2007-03-01 03:26:35 · 5 answers · asked by Mysterious 2