Recent content by catalyst55

oh, thanks a lot guys. it's so much quicker and easier if i just cancel (u+1)^2 and 1/(u+1), leaving just (u+1) instead of expanding and then trying to simplify... seems like i approached this q in the most inefficient of ways -- i even had x= ln (u+1) lol... i had like e^[ln(u+1)] =...

hey, im trying to integrate the following: e^(2x)sqrt(e^x - 1) if only it were e^x at the front - it'd be so much easier! anyway, letting u=e^x-1 and doing everything i eventually get the following (and this is where i get stuck): [ u^(5/2)+2u^(3/2)+u^(1/2) ] [ 1/(u+1) ] du...

Let T1 be the time taken by a ray of light to make a return trip between two mirrors aligned parallel to the Earth’s assumed motion through the aether.Let T2 be the time taken by a ray of light to make a return trip between two mirrors aligned perpendicular to the Earth’s assumed motion through...

Hi, Could someone please help me out here? state the implied domain and range of B) tan (2arccos(x)) ok, the domain of tan for which arctan exists (conventionally) is (-pi/2 , pi/2) -- really the domain of tan is R, but we're using the restricted one. therefore, we know that the...

A spacecraft (Lo = 80 m) travels past a space station at speed 0.7c. Its radio receiver is on the tip of its nose. The space station sends a radio signal the instant the tail of the spacecraft passes the space station. (a) What is the length of the spacecraft in the reference frame...

Ah, i see. Thanks.

Hi, This is the q. I'm pretty sure that they've got it wrong. Two cars A and B pass each other at a speed of 0.18c. A person in car B says her car is 6.00m long and car A is 6.15m long. What does a person in car A measure for these two lengths? Obviously, the person in car A would...

Hi, I've just got the following question for you guys... Say that Bob is traveling away from the Earth at 0.9999c in a glass spaceship. Phil, who is on Earth and can see Bob’s spaceship, notices that Bob’s clock is running slow. That makes sense. HOWEVER, since there is no ideal frame of...

elastic potential energy

Hi, Does anyone have any good resources on CE transistor amplifiers? Preferably ppt presentations or something... I've done the preceding questions, but i can't do 30a... How would i go about doing it? Thanks

Hi The preceding question asks to find the total resistance of the connecting lead between lamp 2 and the battery. This is easily done by modelling the resistive lead as a resistor and drawing the appropriate circuit diagram. This gives: R/(R+12) = 1/12, hence R = 1.1ohm So the...

http://members.optusnet.com.au/boris_m/qqq.jpg Q) Calculate the voltage at lamp 3. i've apparently oversimplified the question with my answer of 10v. the real answer is 9.4v. if anyone could that could help, that'd be great.

apparently so...

You mean the Doppler effect? But.. if the mirror was stationary (say, on earth), the light incident on it would exert a force on the mirror pushing it towards the wall. How would the doppler effect explain this? The mirror is not moving... i always perceived the dopper effect sensually...

Thanks, Edgardo. It's quite intriguing. What I'm wondering about is: Let's say that there's a perfectly reflecting mirror in space and it is hit by incident sunlight. The sunlight experiences a change in momentum and consequently accelerates the mirror. The energy of the light is the same...