@icandothis45 - You know the equation (wavelength)(f)=v, and from the graph, you know both the wavelength (0.6m4) and the frequency (in one second, it completes 2 cycles). The new frequency is 4 after you double it; just multiply 2.44 to get the new average speed.
Thanks so much for the help @glasshours ! Do u have an idea how to do 18 the one with the rocket 4000kg.
Computer Science A thursday and APUSH friday then stats wednesday, macroeconomics thursday and human geography friday and then I’m free!
@glasshours you are helpful! goodluck to you i hope you and everyone else gets their desired score on this test! :)>-
Can someone just go over basic lab equipment to use for each concept like photogate for velocity, etc. etc.???
You first have to determine the average force during the first time interval, which from 0-2 seconds is roughly 400-500N, given that the decrease in force appears to be generally linear. We can then use F=ma on this section, and conclude that the average acceleration from F=ma during the time period was around .1 m/s^2 to .12 m/s^2, which for two seconds now means that the current velocity is .2 to .24 m/s. We know that no force is inputted from 2-3 seconds, and move on to the last time interval, where we have 500N of force for a 1 second time interval, which gives us an acceleration of -.125 m/s^2 for one second, which reduces our velocity to somewhere around .1 m/s, and yields the answer, B.
Wait for which pipes are the harmonics only allowed to be even? I remember that for a specific type of pipe, the harmonics could only be (even or odd not sure which)
@rdeng2614 Closed pipes can only be on odd harmonics. Open pipes can be all harmonics.
Ok thanks.
I got a 39/50 on this, but I have no confidence in myself. Honestly, a lot of the things I got wrong were just reading the question wrong or rushing through it at the end so i can sleep… I think the wording will be the hardest part. And holy cow was there a lot of momentum stuff. There’s a lot of subtle things on this test, make sure you all watch out for that tomorrow
Thanks for the help guys! Can some one help me with 39 i am getting a difference of 12.5J .5kx^2? Thanks
@theboss262 39/50 is great. Be confident in yourself and you’ll be fine!
Good luck everyone! I am going to rest my brain for tomorrow… especially after an intense calculus test today…
@theboss262 Holy cow 39/50 that’s fantastic. Considering those are all “bad” questions thrown out by the college board (which means they’re confusing/hard), you’ll be fine on the AP test.
I got a 30/50.
I wish everyone the best of luck. Remember, even if you feel like you are unprepared, have a strong sense of optimism for the test. Make sure to skim the concept outline, too. I am expecting a curve of 5 for 65-70% 4 for 50-55% and 3 for 35-40%.
What is the equation x=Acos(2pi…) used for? Is this for a spring or for a wave?
@tealpanda - Thanks, good luck to you too 
Really hope the test won’t be too different from that practice test. 12 HOURS
@rdeng2614 - You only need to know how to graph sine and cosine functions for physics 2. Any graphing questions on tomorrow’s test can be solved using logic/information about displacement, spring constant, etc. (But to answer your question, angular velocity = 2pi*frequency)
@glasshours That’s an equation that we learned. I just want to know what it means and when to use it.
Thanks
I want to get some more practice done tonight–anyone know where I can get accurate collegeboard-like questions?
Where can I get answers to the provided free response questions?
if anyone’s still around, can you explain center-of-mass velocity? I hadn’t even heard of the term until a few days ago :-S