Physics - April 2007

001
An athlete swings a 5:72 kg ball horizontally
on the end of a rope. The ball moves in a
circle of radius 0:906 m at an angular speed of
0:696 rev=s.
What is the tangential speed of the ball?
Answer in units of m=s.
002
What is its centripetal acceleration? Answer
in units of m=s2.
003
If the maximum tension the rope can with-
stand before breaking is 50:9 N, what is the
maximum tangential speed the ball can have?
Answer in units of m=s.
004
An airplane travels 94 m/s as it makes a
horizontal circular turn which has a(n) 2.3 km
radius.
What is the magnitude of the resultant
force on the 66 kg pilot of this airplane? An-
swer in units of kN.
005
In the spin cycle of a washing machine, the
tub of radius 0.237 m rotates at a constant
rate of 733 rev/min.
What is the maximum linear speed of the
water inside the machine? Answer in units of
m/s.

2007-04-02 05:37:37 · 1 answers · asked by elquida25 1

A mass m1 is connected by alight string that passes over a pulley of mass M to a mass m2 as shown in the figure. Both masses move vertically ans there is no slippage between the string and the pulley. The pulley has a radius of 30 cm and a moment of inertia of MR^2. If m1 is 4.0 kg, m2 is 3.0 kg, and M is 6.0 kg then what is the acceleration of the masses??

please help, thanks

2007-04-02 05:32:03 · 1 answers · asked by Anonymous

I have to design an experiment to determine how light intensity varies with wavelength, using an LDR to measure intensity. I have two questions really: 1) why do most people seem to have done this using a diffraction grating to get different wavelengths when simple filters would surely give a much more accurate single wavelength that you can determine by looking at its colour. Is there an advantage of a diffraction grating over filters that I am missing? 2) How exactly can the resistance of an LDR be converted to a value in kW/m^2 for the intensity of light hitting it? Is there an equation? Any help with these two things would be very much appreciated, especially if you are currently doing the same coursework. Thanks in advance!

2007-04-02 04:35:40 · 3 answers · asked by Anonymous

2007-04-02 04:17:09 · 1 answers · asked by cameron_hedayati 1

2007-04-02 04:01:15 · 12 answers · asked by science student 2

2007-04-02 03:39:15 · 6 answers · asked by john 3

: electrical current from the thermic column and ambient vortexs caused by the motion of traffic?

2007-04-02 02:52:17 · 5 answers · asked by Anonymous

2007-04-02 02:50:40 · 2 answers · asked by Anonymous

How often do the polarities at the north pole & south pole invert? is it every 10,000years 100,000years or possibly less? Could this change be causing the strange happenings in certain places around the world? When will north be south & visa/versa?

2007-04-02 02:36:36 · 6 answers · asked by ChaliQ 4

If gravity pushes everything to its center or a centripital force, why do atoms and molecules float in the air, shouldn't they be attracted by gravity as all the mass?
Im confused

2007-04-02 02:35:11 · 3 answers · asked by Diana D 2

Has anyone seen proof of this, do people think its possible?

2007-04-02 02:34:58 · 12 answers · asked by Anonymous

: into the singularity cause a vortex on it's event horizon that could generate rotation that power could be grided from?

2007-04-02 02:28:27 · 2 answers · asked by Anonymous

can u tell me what will happen inside the transistor when external voltage is applied.Then why we have to apply D.C voltage through it. How it amplifies the input.

2007-04-02 02:24:58 · 1 answers · asked by asook k 1

A 1.00 kg block of ice at 0 degrees C is added to a picnic cooler. How much heat will the ice removeas it melts to water 0 degrees C?

2007-04-02 02:19:19 · 3 answers · asked by Hannah 1

I saw the movie PAY CHECH in that movie there is a conversation about time machine ie; if we can travell more than the speed of light the concept of time machine will be true is it correct? did Einstein proove it? if so what is the formula? plz give me answer with scientific evidence

2007-04-02 00:50:06 · 3 answers · asked by mot 1

please explain the link between the following:

supersymmetric(SUSY) particles
fermions & bosons (what are these paticles??)
string theory
SUPER string particles
Theory of everything (TOE)

2007-04-02 00:10:20 · 3 answers · asked by sh 1

please explain to me the relationship between these terms/theories:

QED(quantum electrodynamics)
QCD(quantum chromodynamis)
weak force
strong force
massive bossons
fermions
Higgs particles (do these give mass to others???? !)
and this leads to sayin that a photon has mass???

2007-04-01 23:49:32 · 2 answers · asked by sh 1

My Physics teacher has 'blessed' us with this aerodynamic practical... and my work group is stumped.

AIM: To create a device that will trael as far as possible when relesed from a 1 metre high ramp at a 45 degree angle.

APPARATUS:
Cardboard
Paper
Scissors
Glue/stickytape
glitter
streamers
feathers
plastic drinking straws
wooden skewers.

The whole idea of this prac is for the device to travel as far as possible after it leaves the 1 metre ramp.

We have thought of some possible ways. If we made a ball out of paper, and glued glitter to the outide, the ball would have traction due to the glitter. Also, we thought of placing a piece of cardboard down the bottom of the ramp so the device has a smooth surface to go over at the end of the ramp.

Please help as this has really got me and my science group stuck! Thanks!

2007-04-01 23:26:18 · 5 answers · asked by rainbow fun 2

sits 2.0 m from the center. Child B has mass 40 kg. How far from the center must child B sit for the seesaw to balance?

2007-04-01 22:48:03 · 3 answers · asked by Anonymous

A light ray enters the system and is reflected once off each mirror. Through what angle is the ray turned?

a) 210 degrees
b) 180 degrees
c) 120 degrees
d) 150 degrees

2007-04-01 22:27:28 · 2 answers · asked by The one and only 3

The two antennas radiate in phase at a frequency of 5.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned north of east from the antennas, at which destructive interference of the two radio waves occurs, is closest to:

a) 13 degrees
b) 9.7 degrees
c) 19 degrees
d) 6.4 degrees
e) 16 degrees

2007-04-01 22:19:32 · 2 answers · asked by The one and only 3

The power of the lenses of her eyeglasses is -3.00 diopters. Without eyeglasses, the far point of the girl is closest to:

a) 0.25 m
b) 0.50 m
c) 0.33 m
d) 0.17 m
e) 0.42 m

2007-04-01 21:57:26 · 2 answers · asked by mailyn215 1

The image of this object is located:

a) 8.57 cm to the left of the lens
b) 30.0 cm to the left of the lens
c) 60.0 cm to the right of the lens
d) 60.0 cm to the left of the lens
e) 8.57 cm to the right of the lens

2007-04-01 21:48:15 · 2 answers · asked by mailyn215 1

17. The area around a charged object where the electric force interacts with other charged objects.

18. A neutrally charged particle in the nucleus of an atom.

19. The area in which magnetic fields of atoms are lined up in the same direction.

21. A ______ allows current to take an unintended path.

22. The difference in electrical potential energy within a circuit.

23. If an atom has three protons, it also has three _____.

24. A material through which electric charges can easily flow.

21.

2007-04-01 17:23:49 · 2 answers · asked by Answer Champion 3

2007-04-01 16:59:39 · 4 answers · asked by Hakim A 1

seems science is trying harder to prove against creation rather than for creation.

2007-04-01 16:58:06 · 11 answers · asked by james h 2

a) All EM waves travel at the same speed
b) radio waves
c) microwaves
d) ultraviolet
e) infrared

2007-04-01 16:29:15 · 3 answers · asked by mailyn215 1

which statement about images is correct?

a) a virtual image cannot be viewed by the unaided eye
b) a virtual image cannot be photographed
c) mirrors always produce real images because they reflect light
d) a real image must be erect
e) a virtual image cannot be formed on a screen

2007-04-01 16:26:26 · 2 answers · asked by mailyn215 1

A ball on the end of a string is revolved at a uniform rate in a vertical circle of radius 60.0 cm, as shown in Fig. 5-33. Its speed is 4.10 m/s and its mass is 0.300 kg.

a) Calculate the tension in the string when the ball is at the top of its path.
Answer in Newtons.
(b) Calculate the tension in the string when the ball is at the bottom of its path.
Answer in Newtons.

This should give you the link to the picture. If not, I can email. Let me know.

2007-04-01 16:20:25 · 1 answers · asked by Jessie L 2

Assume no gravity and no friction. A small piece of putty of mass 40 grams with neglible size has a speed of 1.3 m/s. It makes a collision with a rod of length 6 cm and mass 6g ( initially at rest) such that the putty hits the very end of the rod. The putty sticks to the end of the rod and spins around after the collision. The rod has a moment of inertia of (1/12)* m *r^2.

A.) What is the angular momentum of the system relative to the center-of-mass after the collision. Answer in kg*m^2/s

B.) What ist he system's angular speed about the center-of-mass after the collision. Answer in rad/s

C.) What is the percent ratio of Ef / Ei % of the energy of the system after the collision to the energy of the system before the collision.

Each question is based on the previous and I am stuck on A. From linear momentum conservation I get the final mass to be going .509804 m /s.I then converted this to angular speed by V/R, to be .509/.06 = 8.496. Then plugged into L=I*angV, but this didn't work

2007-04-01 15:06:08 · 1 answers · asked by Anonymous