Recent content by petern

Well you would do c^2 = a^2 + b^2. Since it is a 45 degree angle, you would do .1/sq. root of 2 for two of the vectors. You would just use .1 m for the third vector. I've plugged in the number and added the 3 together and it doesn't work. Also, can you help me on the 2nd question?

I know I'm suppose to use the equation F = (kq1q2)/r^2 I tried doing [.1/sq. root (2)] m for two of the forces and just .1 m for one. I plug all the numbers into the equation and add up the 3 but it doesn't work. I really have no clue what to do with this. Please help.

I'm assuming I need to use angles but I really can't tell what is is from the sketch.

Homework Statement A person 1.62 m tall wants to be able to see her full image in a plane. a) What must be the minimum height of the mirror? b) How far above the floor should it be placed, assuming that the top of the person's head is 15 cm above her eye level? Draw a ray diagram...

Homework Statement http://img368.imageshack.us/img368/9489/physicszv8.jpg Homework Equations (1/f) = (1/p) + (1/q) The Attempt at a Solution I tried solving this but I don't know what the original P was so I can't solve for q. How can I solve this?

How would I make a working equation for that? I currently have vibration = (x/v) x f. I used x = xo + vt but I don't know which eq. to use to add the f in.

Homework Statement A guitar string is set in vibrations at a frequency of 437 Hz. How many vibrations did the guitar's string make while the sound propagated 235 m in the air? Homework Equations V = wavelegth x freq. The Attempt at a Solution I figured out that you do 437 Hz x...

[SOLVED] Please Check to See if I'm Doing Work-Energy Problem Correctly Homework Statement A child riding a bicycle has a total mass of 40 kg. The child approaches the top of a hill that is 10 m high and 100 m long at 5 m/s. If the force of friction between the bicycle and the hill is 20 N...

[SOLVED] Find Change in Temperature Homework Statement An electric drill bores through a .100 kg piece of copper in 30 s. Find the increase in the temperature of the copper if the drill operates at 40 W. Assume that the drill does not increase in temperature. Homework Equations Q =...

Thank you so much. I finally figured it out. I would use W = K and set that to W = Fxcos(theta) Then I divide K by x which gives me F which is the force of tension.

I finally got it to work. I never knew you could set K equal to Q. How can I get work to be force of tension?

I'm sooo confused. For 2, you're not given mass and you can't set K = 1/2 mv^2 equal to Q = mcT. You can't cancel it out even if you used W = K because Q is not work. I need help getting v to work. For 3, I did 1/2(1.5)(2.1^2) + 1.5(9.8)(.37) = 8.47 J I did 1/2mv^2 + Fx. Edit: I just realized...

For the second problem, I don't know what to do with the velocity because mass is not given so I can't use K = 1/2 mv^2. You're not given height either so there's no way to find the potential energy. For the third problem, I use W = K and so I add K with work = force*distance. The answer is...

I did try harder but I just didn't include it all. I already got to the part where I know K final = K initial - U final but the problem is that I don't know what do with the 15 km.

[SOLVED] Work and Energy Problems I have a few work and energy problems I don't understand at all. Please help. While traveling to school at 27 m/s your car runs out of gas 15 km from the nearest gas station. If the station is 16 m above your current elevation, how fast will the car be going...