hand cranked radio question (ignore - figured out)
Your two friends argued whether they should crank more cycles (e.g. 180 cycles in 1 minute) or longer time (e.g. 180 cycles in 2 minutes) to efficiently charge the internal batteries. They couldn't conclude with their knowledge and decided to...
Homework Statement
I am confused on the drawing below, is the direction of the torque exerted by tension T1 positive or negative?
http://img444.imageshack.us/img444/5190/katrolrh3.jpg
http://g.imageshack.us/img444/katrolrh3.jpg/1/
Homework Equations
The Attempt at a...
Does anybody have any idea of whether or not a non-metallic trigger could be used in sodium acetate heat packs. The crystalisation preocess in the packs is triggered by bending the metal disks inside them which causes heterogeneous nucleation.
Are there any plastics which could work where...
The other day on the radio the DJs were arguing over whether or not you should tip the cable guy after he comes to your house and fixes your TV. Uhhhh why? Why should you tip someone for doing their job? Why should I tip the mailman or garbage man for doing their jobs (which a lot of people...
Can someone give me a hand with these questions because I am really stuck on these!
I am stuck on both these questions, I have no idea where to begin I was given a worksheet which our instructor will review with us but I would like to know how to do them before class. I finished most of it but...
Homework Statement
What is the angular speed of the tip of the minute hand on a clock, in rad/s?
Homework Equations
I thought the equations needed would be angular velocity= change of theta/change in time.
The Attempt at a Solution
I worked on this one and am sure it has a...
please help how can i solve these qustion i should send it to the prof today
1)a ball was thrown horizontally with an initial velocity of 20 m/s from the edge of a building of a certain high. the ball lands at a horizontal distance of 82.0m from the base of the building. What is the height of...
Homework Statement
A,B,a are constants. sketch two or more isotherms on a P-V diagram. V needs to be the independent variable. Mark clearly the intercepts and asymptotes. One graph for a p -->0 and one graph for p--> infinity.
Homework Equations
V=Vo (1-AP/(B+P))(1+ aT)
y=mx+b
The...
Homework Statement
ok can someone tell me how to determine if three vectors form a right hand triple? and why does (a-b)x(a+b)=2(axb)...
please someone help, I am really confused on how to do these... arent just three vectors a right hand triple if the dot product between them all is 0?? I...
Homework Statement
Find the probability of a bridge hand (13 cards) with the AKQJ of spades and no other spades.
Homework Equations
P(event)=\frac{\# \ \\favorable \ \\outcomes}{total \ \# \\outcomes}
nCr=\left(\begin{array}{c}n\\r\end{array}\right)=\frac{n!}{r!(n-r)!}
There are...
Homework Statement
http://www.cramster.com/Answer-Board/Image/20073231626286331026398833900007956.jpg
This is not problem. I just having trouble understanding the basics. Please just tell me right away, don't 'assist!'
I trying to understand the right hand rule. Here are to...
Hello guys,
First of all I have small question with the electric motor. I just learned today in class that with electric motor loops the current is reversed in the loop after 180 degrees to continue a constant movement in one direction. But my question is why is this nessecary. If we don't have...
Hi everyone, I am new here, and I am thirteen, but I am really into this and I have recently grasped (only on a basic level) quantum theory. I understand relativity and I am looking into many fields, such as cosmology.
So, me and my dad were talking the other day, and he proposed the...
How colud you intergrate (4X^3-7X^2+6X-3)/(X^6-4X^3) by hand (my TI-89 gave me -[2(13*2^(1/3)-12)(√3*2^(1/3))X^2*Arctan[√3-*2^(1/3)(2X+2^(2/3))/6]+2^(2/3)+28√2+13)X^2ln(X62+2^2/3X+X^(4/3)+2(2^(1/3)(14*2^(2/3)*X^2ln|X-2^(2/3)|-6(14X^2ln|X|)+2(4X-1)))))]\96X^2
i tryed to use partial fractions...
Hey
I am trying to figure out how to use the right hand rule when magnetic force points downward. I comprehend what the fingers are used for but when i but the finger downward I get a direction to the left, but the answer is that the direction is north. Why is that?
[SOLVED] hand rule application (dir of mag force)
Homework Statement
You witness an experiment with a wire (a part of a circuit) and a horseshoe magnet. It begins with a wire laying on a table and passing through the mag field of the horseshoe magnet, but with no current passing through the...
1. Homework Statement
Let a=(1,2,3) b=(-1,2,-1) and c=(0,1,-2). Do these vectors taken in this order, satisfy the right hand rule? Explain.
3. The Attempt at a Solution
I was told a cross b must equal c otherwise this is not satisfying? I'm VERY confused...can someone help out...
Magnetism! Help!
can someone please explain the hand rule thing to me...i am dead lost when teacher is explaining it. All i know is that your thumb is N and the bottom of your hand is S...please help!
[SOLVED] Right Hand rule, explain please?
I don't have a problem, I just have issues with understanding the right-hand rule, if someone could explain it (with pictures if possible) I would appreciate it, although it might be better in person because I could see the motion.
[SOLVED] How would one factor this.. by hand..
Assuming I didn't know the perfect square formula ( (a+-b)^2), how would I go about solving this equation by hand factoring?
x^2 + b/a *x + b^2 / 4a^2 = 0
I am trying to figure out how the quadratic formula is derived, and this is one part of...
1. Use the sandwich theorem to compute the limit as n goes to infinity of the sequence with the following nth elements:
a(n) = [1 + sin(n*pi/3)cos(n*pi/5) ] / [n^0.5]
I would really appreciate some help with this one guys. If you could please go slow with the answer as my trig is pretty...
Homework Statement
Clock hands move slowly but they do have a small angular momentum. According to the right hand rule, in which direction, with respect to the clock face, does the angular momentum vector point?
Homework Equations
right hand rule
The Attempt at a Solution...
Combustion reaction -- discrepancy between hand calc. and computer sim
I am considering the reaction C2H4O (liquid) --> CO + 0.5CH4 + 0.5H2 + 0.25C2H4
I calculated the flame temperature when the reactant is at 298 K and 20 atm using H(reactants) = H(products) to get Tfinal = 945 K.
I then...
religious nuttiness reaches a new low (well I guess it isn't just religious...):
http://www.upi.com/NewsTrack/Top_News/2008/01/09/man_severs_hand_to_escape_gods_wrath/1800/
Tsu happened to see this and said that it looks legit [i.e. it appears to be a genuine x-ray of a hand].
"This is what happens when you hold the firecracker for too long."
http://my.break.com/content/view.aspx?ContentID=408271
Homework Statement
\frac{d^2}{dz^2} [ (z^2) \(\frac{-(z-\frac{1}{z})^2}{20+8(z+\frac{1}{z})} \frac{1}{iz}]
Homework Equations
The Attempt at a Solution
I have to do this by hand no calculators, CAS, or tables. I started by just expanding things and using the quotient rule...
Right hand rule for Spinning things...
Hi, I'm havign a hard time figuring out how the right hand rule works for Angular momentum, Angular velocity and torques.
Its so confusing because At university we get problems about rotating solid bodys like a disk on a rod, and when the question...
Hello all,
I have to design a hand crank generator to produce power for some downstream application. The amount of power is on the order of that needed for anything between a heavy-duty flashlight to one of those desktop mini-fridges that hold one soda can.
Thing is, I'm drawing a blank on...
so, for the very specific cases of linear systems
i can identify what shape it will be after determining the eigenvalues, but i really do not know how to go about sketching the phase planes.
can someone give me a method?
Homework Statement
A charged particle is moving perpendicular to a magnetic field B. The table below shows the relationships between directions of three vector quantities. Notice that one entry is missing from each column of the table. Your job is to complete the table. Enter your answers in...
Homework Statement
http://img206.imageshack.us/img206/5084/71282075fy0.jpg
Homework Equations
There are many variations on the right hand rule, but I'm most confortable with the following. Current is in the direction of thumb, B field is in direction of fingers and F shoots out of the...
man i don't understand this stuff i have a test on thursday and i found some practice problems can anyone help me solve these( please show work) i need to learn how to do them i have the formulas i think but idont know when and which to use please help soon
1. In 1993, Bill tossed a ball...
Hello friends,
I am studying in 10th class. Actually I have a question and I’m unable to solve this question. My question is: How can we find the square root of a number by hand? How about cube roots? If anybody can solve my question I will grateful. Thanks in advance!
I have been handed a challenge that is beyond my reach.
I need a way to detect the change in skin conductance, or some other electrical signal on the surface of your hand when you lightly touch your forefinger and thumb together. In this configuration, the skin sensors have to be located on...
A daring ranch hand sitting on a tree limb wishes to drop vertically onto a horse galloping under the tree. The constant speed of the horse is 10.0 m/s and the distance from the limb to the level of the saddle is 3.00 m. (a) What must be the horizontal distance between the saddle and the limb...
Homework Statement
A proton traveling at a speed of 3.0 x 10^6 m/s travels through a magnetic field of strength 3.0 x 10^-3 T, making an angle of 45 degrees with the magnetic lines of force. What force acts on the proton?
Homework Equations
F = QvB
The Attempt at a Solution
I...
Homework Statement
Not an actual HW problem, but related to a lot of probs I'm doing.
Lets say a hand pushes a block across a surface (with friction).
You take pic of 2 timepoints
1) when hand pushes block
2) After hand has let go and block is slowing due to friction
Now when I draw the...
Question
A 54.0kg ice skater spins about a vertical axis through her body with her arms horizontally outstretched, making 2.50 turns each second. The distance from one hand to the other is 1.5m. Biometric measurements indicate that each hand typically makes up about 1.25% of body weight...
calculating SCIENTIFIC NOTATION by hand help please.
((4*10^5)(5*10^-7)) / (2*10^-3)
im getting 10 and the answer but its should be 100 can you please tell me what i am so posted to do step by step please.
Homework Statement
http://img329.imageshack.us/img329/9304/righthandcq2.jpg
The Attempt at a Solution
For this method I was taught that the direction of the fingers points in the direction of velocity, the thumb in the direction of the magnetic field, and the force would shoot out of...
Homework Statement
http://img71.imageshack.us/img71/8453/untitleddt6.jpg
Imagine that current flow from east to west. what is the direction of the force on the current when the magnetic field B is (i) to the East and (ii) Vertically up?
The Attempt at a Solution
I've done a bit of...
(a) What is the angular speed of the second hand of a smoothly running analog watch?
____ (rad/s)
i got 0.03 pi
webassign says "Check the syntax of your response"
i also tried 0.03, but it's wrong also..
how do i put my answer?
Homework Statement
There seem to be three right hand rules for dealing with magnetic field, current, and force, and I don't quite understand how to use them.
Namely, I'm having trouble understanding why two parallel wires with current flowing in each of them attract if the currents are in...
Estimate the maximum pressure that would be applied to your hand if oyu were told it out of an open car window while the car travles at 70mph through still ait at 20 degrees c what would be the maximum pressure applied to your hand if the car where a formula one race car traveling at 220mph
I...
cos(arcsin(-1/3)) how to do it by hand??
Homework Statement
Solve without a calculator
cos(arcsin(-1/3))
The Attempt at a Solution
now i have fount the solution to be (-2/3)(2^(1/2)) now not only did my calculator come up with that but between the SSS formula and pythagorean formula(...