Can someone explain to me what i did wrong on this quiz? waves

AI Thread Summary
The discussion revolves around a quiz question related to wave physics, specifically the correct units for velocity and acceleration. The original poster is confused about receiving a deduction for writing "m/s" instead of the correct "m^2/s^2" for velocity squared. Participants clarify that the units for acceleration involve "m/s^2" and that "d^2y/dx^2" has units of "1/m." The conversation also includes a light-hearted exchange about attending Penn State. Understanding the correct application of units in physics is crucial for accurate quiz responses.
mr_coffee
Messages
1,613
Reaction score
1
hello everyone. I'm studying for the exam now and I understand if a wave is moving in the negative x direction to the left, the value infront of the x should be positve. But you see where he took off -1/2, because i wrote down m/s? Do you know why? its v^2, i thought that just means take the value of v, square it. should it have been m^2/s^2?

http://img112.imageshack.us/img112/5643/lastscan4bc.jpg

Thanks!
 
Last edited by a moderator:
Physics news on Phys.org
looks like you go to PENN STATE
Physics 211 212 213 214

SORRY I CANT HELP, but i thought your class looked like a penn state class 214, just got me happy! sorry lol
 
Last edited:
Yes, it should have been m^2/s^2. Note that the d^2y/dt^2 is in m/s^2 and the d^2y/dx^2 is in 1/m.

So:
\frac{m}{s^2}=(unit)\frac{1}{m}

\frac{m^2}{s^2}=(unit)

-Dan
 
Ooo thanks topsquark!
and yes I go to Penn state hah! I'm assuming u also went there or go?
I'm a Computer Engineering Major, wee!
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'A bead-mass oscillatory system problem'
I can't figure out how to find the velocity of the particle at 37 degrees. Basically the bead moves with velocity towards right let's call it v1. The particle moves with some velocity v2. In frame of the bead, the particle is performing circular motion. So v of particle wrt bead would be perpendicular to the string. But how would I find the velocity of particle in ground frame? I tried using vectors to figure it out and the angle is coming out to be extremely long. One equation is by work...
Back
Top