2. Can a 20 N force and 40 N force ever produce a resultant with magnitude of 27 N? 3. A 60.0 km/h wind is blowing due north. What is the magnitude and direction of the velocity of an
airplane traveling at an air speed of 150 km/h when it is heading (a) north; (b) south; (C) east? Solve
mathematically.
4. An automobile travels 40 km due east and then 60 km due north. (a) What is the magnitude of the
resultan displacement of the automobile? (b) What is its direction including angle?
Solve mathematically.
5. Determine whether each of the following combinations of forces can be in equilibrium if their directions
are properly selected:
(a) 5 N, 7, 13 N (b) 5 N, 7 N, 9N
(C) 5 N, 7 N, IN

Air flows upward in the wick of a lantern because of the liquid property called

Fft review: linspace, fs, fftshift, nfft 1. generate one second of a cosine of w,-10hz sampled at f, = 100hz and assign it to x. define a tt as your time axis 2. take 64 points fft. 3. as you remember, the dft (which the fft implements) computes n samples of s2t where k-0,1,2, n -1. plot the magnitude of this 64-points fft at range 0 to 63, what do you think of this graph? 4â·to get the x-axis into a hz-frequency form, plot this 64-points fft between-50 to 50 (the 100hz sampling rate) and have n-points between them. 5. according to your figure, what frequency is this cosine wave at? 6. remember that the fft is evaluating from 0 to 2ď€. we are used to viewing graphs from-ď€ to ď€. therefore, you need to shift your graph. 7. now according to your shifted graph. what frequency is this at? 8. note that the spikes have long drop-offs? try a 1024-point dft. note that the peak is closer to 10 and the drop-off is quicker. although, now sidelobes are an issue

The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2