**A mass m2 = 1.5 kg is initially moving with velocity vo. It collides completely inelastically with a block of mass m2 = 2.0 kg. The second block is attached to a spring with a spring constant of k = 5.6x10ʻN/m. The
block and spring lie on a frictionless horizontal surface. The spring compresses a distance of 0.20 m upon
collision
(a) What is the velocity of the mass mi and the block immediately after the collision?
(b) What is the initial velocity of the mass mi immediately before the collision?
(C) If the block were attached to a long string and hung as a pendulum, how high would the block and mass
mi rise after the collision?

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies. molten iron has a density of 7.0g/cm cubed. in its solid state, iron has a density of 8.0g/cm cubed.

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.

How do we measure or think of speed in the united states?