# Posts by Rick

Total # Posts: 355

**physics**

A camera is supplied with two interchangeable lenses, whose focal lengths are 35.0 and 150.0 mm. A woman whose height is 1.80 m stands 7.00 m in front of the camera. What is the height (including sign) of her image on the film, as produced by (a) the 35.0-mm lens (b) the 150.0...

**physics**

A person stands 4.4 m in front of a wall that is covered floor-to-ceiling with a plane mirror. His eyes are 1.9 m above the floor. He holds a flashlight between his feet and manages to point it at the mirror. At what angle of incidence must the light strike the mirror so the ...

**decimals**

1.0 X 21 = 21 or 210 because of the decimal point, I just don't remenber how the decimal point works.

**decimal**

1.0 X 21 = 21 or 210 because of the decimal point. I just don't remember how it works ?.

**decimal**

21 or 210

**decimal**

1.0 X 21 =

**physics**

The human eye is most sensitive to light having a frequency of about 5.3*10^14 Hz, which is in the yellow-green region of the electromagnetic spectrum. How many wavelengths of this light can fit across the width of your thumb, a distance of about 2.0 cm?

**physics**

In astronomy, distances are often expressed in light-years. One light-year is the distance traveled by light in one year. The distance to Alpha Centauri, the closest star other than our own sun that can be seen by the naked eye, is 4.7 light-years. Express this distance in ...

**trig**

8 sin 9x cos3x Rewrite the xpression as a sum or differnce using one of the product sum formulas Simplify if possible

**trig**

Prove the identity sin squared 0 with line/2 = csc zero with line -cot zero with a line /2csc zero with a line

**trig**

Use half-angle formulas to find the exact value for the following cot 75 degrees

**trig**

Graph the followiing function from x + 0 to x = 4 pi y = 3 cos squared x/2

**trig**

If cos A =1/3 with A in QIV find cscA/2

**trig**

Prove the identity sin(3 pi /2 + x) + sin(3pi/2 -x) = -2cosx

**trig**

If tan(A+B) = 2 and tan B =1/3, find tan A

**trig**

Graph one complete cycle of y + cos x cos pi over6 + sin x sin pi/6 by first rewriting the right side in the form cos(A-B)

**trig**

Graph the following from X = 0 to x = 2 pi 2cos 6x cos4x + 2 sin 6x sin 4x

**trig**

Prove the identity sin (3 pi/2 + x) + sin (3 pi/2 -x) = -2 cos x

**trig**

If sin = -3/5 with A in QIV, find cos A/2

**trig**

If sin = 4/5 with A in QII, and sin B = -3/5 with B in QIV find cos(A-B)

**physics**

A generating station is producing 1.3*10^6 W of power that is to be sent to a small town located 7.0 km away. Each of the two wires that comprise the transmission line has a resistance per kilometer of length of 5.0*10^-2 /km. (a) Find the power lost in heating the wires if ...

**physics**

Suppose you wish to make a solenoid whose self-inductance is 3.0 mH. The inductor is to have a cross-sectional area of 2.0*10^-3 m2 and a length of 0.052 m. How many turns of wire are needed?

**physics**

The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.5 m. The magnetic field of the generator is 0.10 T, and the coil rotates at an angular speed of 25 rad/s. What is the peak emf of this generator?

**physics**

The average emf induced in the secondary coil is 0.10 V when the current in the primary coil changes from 3.2 to 2.0 A in 0.10 s. What is the mutual inductance of the coils?

**physics**

A piece of copper wire has a resistance per unit length of 6.45*10-3 /m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.140 m. The ends of the wire are connected to a 12.0 V battery. Find the magnetic field strength at the center of the coil.

**physics**

In a lightning bolt, 13 C of charge flows in a time of 1.5*10-3 s. Assuming that the lightning bolt can be represented as a long, straight line of current, what is the magnitude of the magnetic field at a distance of 29 m from the bolt?

**physics**

An electric power line carries a current of 1600 A in a location where the earth's magnetic field is 4.0*10-5 T. The line makes an angle of 75° with respect to the field. Determine the magnitude of the magnetic force on a 130 m length of line.

**physics**

There is a 0.225 T magnetic field directed along the +x axis and a field of unknown magnitude along the +y axis. A particle carrying a charge of 7.20 10-5 C experiences a maximum force of 0.455 N when traveling at a speed of 2 104 m/s through the region where the fields are. ...

**physics**

still don't understand where the 20.8V comes into it how u get that?

**physics**

The average power dissipated in a stereo speaker is 54 W. Assuming that the speaker can be treated as a 4.0- resistance, find the peak value of the ac voltage applied to the speaker.

**physics**

where are you getting 22.95% and what is delta T

**physics**

A toaster uses a Nichrome heating wire. When the toaster is turned on at 20°C, the initial current is 1.50 A. A few seconds later, the toaster warms up and the current has a value of 1.22 A. The average temperature coefficient of resistivity for Nichrome wire is 4.5 10-4 (...

**physics**

A car battery has a rating of 200 ampere·hours (A·h). This rating is one indication of the total charge that the battery can provide to a circuit before failing. What is the total charge (in coulombs) that this battery can provide? Determine the maximum current ...

**physics**

A car battery has a rating of 200 ampere·hours (A·h). This rating is one indication of the total charge that the battery can provide to a circuit before failing.

**physics**

An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.11 10-11m. What is EPEfinal - EPEinitial, which is the ...

**Physics**

i don't know what you mean about the charge of the electron? or what number do you times it by.

**Physics**

How many electrons must be removed from an electrically neutral silver dollar to give it a charge of +2.8 µC?

**math**

wat is 45x320?

**algebra**

find the average weight in pounds of a type of bird of your choice. Use the rational exponent equation L = 2.43 * W^0.3326 to estimate the wingspan L in feet of the bird that weighs W pounds show the average weight. How do I show the calculations necessary to find the ...

**Math permutations**

pi=(245)(1354)(125) 1) Write as a product of disjoint cycles. Ans: (14)(253) Is this correct? 2) Solve : pi^2, pi^5,pi^(-1) 3) What's the order of pi? and why?

**Quantiative Methods**

rfdf d fd fd f

**elementary math**

How do you add decimals with partial sums?

**algebra**

write equation of line that passes through P(0,0) and is parallel to given line, x=8y-16, answer in slope intersect form.

**ETH125**

United States-Centric Views Comparison • Resource: Appendix D Did you have this in your studies.Give a copy of Appendix D to a friend or family member and ask that person to complete the table contained therein. In doing so, your chosen participant will consider what he ...

**Pseudocode programming**

I need a currency conversion application. It does not have to be written in an actual programming language, just the pseudocode as well as the elements listed below. Complete requirements analysis Design Verification Validation and test documentation The Currency Conversion ...

**BUSINESS**

C (introducing a new concept

**math function rule input/output**

how do you figure out and what is the easiest way to teach it.

**Sociology**

What are the features of Sociology that distinguish it from everyday speculation on social life?Why did they emerge at the time they did in the 19 th century? This site has some good answers to your first question. http://en.wikipedia.org/wiki/Sociology I don't know who ...

**ALGEBRA2**

100Y^2-4Z^2 What is the problem? Factor? It is a difference of two squares.

**Chem II**

2.5 mol NOCl(g) was placed in a 2.50 L reaction vessel at 400 degrees C. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation: 2NOCl(g)<-->2NO(g)+Cl2(g) Calculate the equilibrium constant, Kc, for the reaction. ...

**science**

tell me about science apparatus They are used in science. You need a much more specific question to get a useful answer. For instance: What is the Hoffman apparatus, and how is it used?

**Please correct sentence**

Although telephones companies always need to build more towers to fulfill the increasing demand for cell phone service.

**Pigskin Geography**

(week 15) identify the state capitals in which a game will be played? Which games? When? Please give us more information so that we can help you.

**Probability**

New York’s MEGAMILLIONS lottery, a player wins 1st prize by selecting the correct 5 number combination when 5 different numbers from 1 through 56 are drawn, then selecting the correct MEGABALL number drawn from numbers 1 through 40. If a player selects one particular ...

**Eyh125**

I am in Eth 125 and I really do not like this class