Do the conduction electrons in a copper wire act quantum mechanically or not? roughly speaking, quantum mechanics comes in when the de broglie wavelength of an electron is comparable to or longer than the spacing between atoms. the lattice constant (roughly the spacing between atoms in a crystal) for copper is about 4 x 10-10 m. the drift velocity of electrons is typically less than 102 m/s under household conditions (b) what about atoms in the interstellar medium? here we want to compare the average spacing between atoms (they move! ) to the de broglie wavelength of an atom. the interstellar medium is mostly hydrogen at an average density of order 1/cm3 and temperature about 3 k. in this case you' need the thermody- namic resul p/(2m)(3/2)kt, where k is boltzmann's constant (c) now let's switch gears to talk abou the uncertainty principle when ligo detects gravitational waves, it is measuring displacements of its test masses of order 10-18 m. the test masses are about 40 kg. what is the minimum uncertainty induced in the velocities of the test masses?

If forces acting on an object are unbalanced, which factors may result fron an unbalanced force? check all that apply

1134567 a jet with mass m = 1.1 ă— 105 kg jet accelerates down the runway for takeoff at 2 m/s2. 1) what is the net horizontal force on the airplane as it accelerates for takeoff? 2.2*10^5 n your submissions: 2.2*10^5 computed value: 220000submitted: saturday, january 26 at 2: 41 pm feedback: correct! 2) what is the net vertical force on the airplane as it accelerates for takeoff? 0 n your submissions: 0 computed value: 0submitted: saturday, january 26 at 2: 41 pm feedback: correct! 3) once off the ground, the plane climbs upward for 20 seconds. during this time, the vertical speed increases from zero to 21 m/s, while the horizontal speed increases from 80 m/s to 95 m/s. what is the net horizontal force on the airplane as it climbs upward? n 4) what is the net vertical force on the airplane as it climbs upward? n 5) after reaching cruising altitude, the plane levels off, keeping the horizontal speed constant, but smoothly reducing the vertical speed to zero, in 13 seconds. what is the net horizontal force on the airplane as it levels off? n 6) what is the net vertical force on the airplane as it levels off?

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?