Physics Questions and Answers January 03, 2020

A pendulum is constructed from a 5 kg mass attached to a strong cord of length 0.9 m also attached to a ceiling. Originally hanging vertically, the mass is pulled aside a small distance of 8.9 cm and released from rest. While the mass is swinging the cord exerts an almost-constant force on it. For this problem, assume the force is constant as the

Recall that Earths age is 4.56 b.y. This age was determined from a meteorite that was found on Earth. The dating method used was U-Pb with a half-life of 4.56 b.y. Based on these facts, you should be able to expect how much U and how much Pb the meteorite should have on it? Avoid general or vague statements, explain your answer clearly with

Compare the relative importance of the electrostatic interactions between degenerate electrons and ions in a normal metal with a density of about 10 4 kg m -3 and in a white dwarf with a density of about 10 8 kg m -3 . In both cases estimates the temperature below which the electrons are degenerate.

6.7. In Example 6.2 it was assumed that (px) 0. Determine the minimum uncer tainty wave function if this constraint is relaxed.,EXAMPLE 6.2 Use the results of Section 3.5 to prove that the wave func tion for which Ax Apx 2 must be a Gaussian. SOLUTION In Section 3.5 we established the general uncertainty relation AAAB (C)2 for observables A and

A PWR fueled with 235 U is initially operating at a power level of 1200 MW t . What is the power of the reactor after 2 minutes for reactivity insertions of -15 cents and +15 cents? Assume a prompt neutron lifetime of 0.1 milliseconds. Note that in 235 U fueled thermal reactors, -1 is about 80 seconds.

Po B and Al 104 sec 1(Gr(() Apo BPo Po exp BPo Po Po Po exp

Consider the two Hertzian dipoles shown below J a h1 2 h Assume A 1, a , h J2 The current densities of the dipoles are specified by the phasors Z 3.(P)21d8(72), 3(7)2 18 Ae 8(72) Id X (a) Can you figure out the angular location of all the nulls and maxima of the radiation pattern by physical reasoning, without calculating radiation pattern

Derive the time-dependence (7.25) for the imaginary channel of the demodulated and filtered signal signal. Fig. 7.3 The shifts in frequency for signals from a uniform sample due to demodulation and filtering, with small offset w.

signal demodulated signal demodulated and filtered signal 000 20,80 (0)