ALan

An object located in front of a concave mirror with a radius of curvature of 80 cm produces an invert image that is three times the size of the object. Calculate the distance between the object and the mirror.

15 years ago

A cathode ray tube operates at 80 kV with a current of 875 uA. Calculate the a)Intesity (# of photons per second f the x-rays b)Minimum wavelength of the x-rays produced by the CRT thanks in advance

15 years ago

Log(base a)(a^4*b)-Log(base a)(a*b) is the same as a)4 b)3 c)3a d)a^3 I got the answer as d since subtracting logs with the same base is division. However, the answer key saids its b, Can someone please help me with this?

15 years ago

A resistor has a resistance R, and a battery has an internal resistance r. When the resistor is connected across the battery, ten percent less power is dissipated in R than would be dissipated if the battery had no internal resistance. Show that the ratio...

15 years ago

A 3.00 uF and a 5.00 uF capacitor are connected in series cross a 30.0V battery. A 7.00 uF capacitor is then connected in parallel across the 3.00 uF capacitor. a)Calculate the equivalent capacitance of the circuit I think the answer is 3.33 uF. b)Determi...

15 years ago

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the pressure formula P=M/V, but i kept subbing in other formulas, but i get stuck..can som...

15 years ago

A pond has the shape of an ice cream cone with the tip slices off and has a depth of 5.00m. The atmospheric pressure above the pond is 1.01 *10^5 Pa. The circular top surface (radius = R2) and circular bottum (radis = R1) of the pond are both parrallel to...

15 years ago

A room has a volume of 120 m^3. An air-conditioning system is used to replace the air in the room every twenty minutes, using ducts that have a square cross ection. Assuming that air can be treated as an incompressible fluid, calculate the length of a sid...

15 years ago

I got stuck after i attempted to use 1/f=1/di+1/do, seeing as how i need di, which i don't have.

15 years ago

Thanks

15 years ago

Using the point slope formula m=(y2-y1)/(x2-x1) m=([1/2]-[1/2])/([-5]-[-9]) m=0/4 m=0 In other words, this is a horizontel line, with a slope of 0 m=rise/run

15 years ago

if you rearrange the question it becomes y=8x-8 Using y=mx+b, with m as your slope, your slope is 8

15 years ago

Sub in t=6 into the formula v=-1/3t+4 v=-1/3(6)+4 v=-1/18+4 v=-1/18+72/18 (4 is the same as 4/1 and when multiplied by 18, 72/18) v=71/18

15 years ago

B) Fault block mountains Happens when two plates collide, and force the rock up.

15 years ago

Yes, if the particle is not in motion, it will not experience a magnetic force (faraday's law) Yes to 2 too, using the third hand rule, fingers pointing in the direction magnetic field (north to south), thumb pointing in the direction of particle movement...

15 years ago

Information you have: m=23kg Fg(1)=185N Using the Fg=mg, you can figure out the force exerted on the suitcase by gravity if there was no force pulling it: Fg=mg Fg=(23kg)(8=9.81m/s^2) Fg=225.63N Fg-Fg(1)=F experienced by handle 225.63N-185N=40.63N

15 years ago

Perms question Since there are 8 students, you say 8! or 8 factorial 8*7*6*5*4*3*2*1 8 first because there are 8 possible choices, 7 for the next one since one student has already been chosen, and so on. Answer is 40320

15 years ago

I typed exactly what is said on the question sheet. Answer given is 5.47*10^15 photons/s As each photon strikes the electron, it is absorbed and then any excess energy is then re-radiated in the form of x-rays, from what i understand, i need to find the r...

15 years ago

Brightness also refers to intensity, or # of photons, what determines the kinetic energy of the ejected electrons is frequencey, as each photon releases 1 electron, if the photon has enough energy to overcome the work function, the remaining energy is the...

15 years ago

This is probably waaaaay to late, but period can be determined using b=180/p b=3 period is 60

15 years ago

W=FD W=(400N)(3.0m) W=1200N I don't really get the 1250N car thing. Unless you also need friction, but i need the coefficent for that.

15 years ago

well, i didn't think of that, if that's the case, v=(-1/3)t+4 Sub in t=6 v=(-1/3)(6)+4 v=(-6/3)+4 v=-2+4 v=2 Hope you read this before you sleep =\

15 years ago

huh....

15 years ago

It decreases very very slightly. Mabye from 9.81m/s^2 to 9.80m/s^2, MABYE. Depending on how far you travel away from Earth, the force due to gravity is decreases exponentially. This can be proven with Fg=Gm1m2/r^2 where G=Gravitational constant(6.67*10^-1...

15 years ago

5 divided by 3, gives you 1.6666666666667 gallons of punch per bowl. In fraction form, it would 5/3 gallons per bowl.

15 years ago

Ooo right, my teacher mentioned that, guessed it slipped my mind. Thanks a lot. Diploma tomorrow :(

15 years ago

Isolate x or y in either equation and then subsitute it in to the other equation. x+y=56 x=56-y Subsitute into the other equation: Since x=56-y, the other equation becomes (56-y)+3y=56 56+2y=56 subtract 56 from both sides 2y=0 y=0/2 y=0 then x must be 56

15 years ago

Thanks a lot!

15 years ago

Thanks

15 years ago

Im sorry! I meant density! It was represented by a small p, so i thought pressure >_< Anyways, density = mass/volumne. My teacher gave me a hint about radius cancelling each other off in the formula manipulation. Hope this helps!

15 years ago

Also, teacher gave me a hint that "r(radius)" was suppose to cancel during the formula manipulation process..

15 years ago

o wow, i didn't even think of the geometrical way, thanks.

15 years ago