Using the ekg simulator posted in elearning, generate 20 cycles of the ekg waveform (when displaying the original, noisy or filtered signals in time-domain, show only two or three cycles). (a) (10 points) display the original ekg signal both in time-domain and frequency-domain. (b) (10 points) add the following two noises to the original signal: - a 60 hz noise (with an amplitude of 1). - an additive white gaussian noise (awgn), i. e. independent and identically-distributed (i. i.d.) gaussian random variables with = 0 and = 2. display the noisy signal both in time-domain and frequency-domain. (c) (20 points) analyze the spectra of the original and noisy signals and design a suitable filter to extract the ekg signal from the noisy signal. display the filter’s response. display the filtered signal both in time-domain and frequencydomain.

Current enters a circuit at a: 1.positive terminal 2.negative terminal 3.low potential side 4.resistor

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.