When you take torque, you take it about a point. First you have to find some point which you like (which can be any point, but you may want to choose something that makes the calculation simple.) Then you look how far the lines of forces are from this point - you drop perpendiculars to the lines...
The book uses g = 9.8 whereas you used 10.
You did well. There is also an equivalent way of doing it which may seem simpler : write down the force equation and the torque equation. For the system to be in equilibrium, both force and torque must be zero. Plug in the values and you're done.
Delphi is correct, noppawit. The formula you use involves the approximation that d is much smaller than D. That's not true here. So you have got to write down the formulas for the path lengths direct : take the distances between each slit and the point x_p. Constructive interference occurs...
2.how can that be wrong??i'm stumped.
3.how would you do it if you were to calculate the distance traveled b/w say,t=1 and t=2?think a bit and I'm sure you'll find a way.
4.the same answer??what you've found there is just the time period of the shm.
remember that a 2pi phase change gives the...
1.The physics part seems to be correct.However I'm getting something like 91 as the answer.if that is close to the correct answer you need to check your calculations,put exact value of pi and stuff.
2.Your calculator is not in radian mode.
3.you know x as a function of t.so you can write t...