What is one example of the use of an infrared sensor? track shipments, monitor building exit and entry, water flows without turning on a facet, or barcode scanner

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Which situation will have the highest resistance? a. long wire and high temperatureb. short wire and high temperaturec. long wire and cold temperaturedshort wire and low temperature

Give your knowledge of these things in your paper, you will compare and contrast analog and digital signals to determine which is more reliable for encoding and transmitting information. you’ll compare these features: signal shape numerical values for signal measurements amount of data that can be transmitted energy requirements privacy and security (ability of the signal to be encoded in a secret code) clarity of signal in the space provided, write down what you already know about any of these features. if you’re not sure, write down questions you might have about the features.