A dry cell, a switch, an ammeter and two resistors Ri and R, are connected in series. An oscilloscope and a voltmeter are connected respectively between the terminals of R. and R 2 as shown in the figure. We close the switch K; the voltmeter displays 3.5V and the luminous line visible on the screen is displaced by two divisions. The intensity of the current in the circuit is 250mA. The vertical sensitivity of the oscilloscope is 1V / d * i * v . 1. Is the terminal COM of the voltmeter connected to Cor B? Justify. ( i P (s) 2. Determine the value of R 2 .(1pt) K R 1 3. What voltage is measured with the oscilloscope U AB Or U RA ? In which way does the luminous line move? (1.25pts) Determine the voltage between A and B. Deduce the value of R 1 . (2pts) 5. Determine the voltage delivered by the dry cell. (1.5pts) 4. R2 777

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.

Física: un futbolista patea hacia el arco con una velocidad de 15m/ah, calcular: a)el alcance para un ángulo de tiro de 25º, b) el tiempo que el balón permanece en el aire.