The lighting needs of a storage room are being met by six fluorescent light fixtures, each fixture containing four lamps rated at 60 w each. all the lamps are on during operating hours of the facility, which is 6 a. m. to 6 p. m., 365 days a year. the storage room is actually used for an average of 3 h a day. if the price of electricity is $0.11/kwh, determine the amount of energy and money that will be saved as a result of installing motion sensors. also, determine the simple payback period if the purchase price of the sensor is $32 and it takes 1 h to install it at a cost of $40.

11. you want to calculate the displacement of an object thrown over a bridge. using -10 m/s2 for acceleration due to gravity, what would be the total displacement of the object if it took 8 seconds before hitting the water?

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

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone