Consider a room that is initially at the outdoor temperature of 20°c. the room contains a 40-w light bulb, a 110-w tv set, a 300-w refrigerator, and a 1110-w iron. assuming no heat transfer through the walls, determine the rate of increase of the energy content of the room when all of these electric devices are on.

As the distance from a magnet increases, what happens to the magnet force?

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?

Relative to the ground below, how many joules of potential energy does a 1000-kg boulder have at the top of a 5-m ledge?