Cuál es la diferencia entre una maqueta y un modelo.

The extremely high temperatures needed to trigger nuclear fusion are proposed to be generated by laser irradiating a spherical pellet of deuterium and tritium fuel of diameter 1.8 mm. (a) determine the maximum fuel temperature that can be achieved by irradiating the pellet with 200 lasers, each producing a power of 550 w. the pellet has an absorptivity 0.3 and emissivity 0.8.

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!

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative