Electromagnetic radiation is emitted by accelerating charges. The rate at which energy is emitted from an
accelerating charge that has charge q and acceleration a is given by
dE/dt=q2a2/6πoc3, (4)
where c is the speed of light.
(a) The electron in a hydrogen atom can be considered to be in circular orbit with a radius of R = 0.0529 nm
and a kinetic energy of KE = 13.5 eV. If the electron behaved classically, how much energy would it
radiate per second?

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Suppose an objects initial velocity is 10m/s and it’s final velocity is 4 m/s. mass is constant. what can best be concluded about the object based in the work-energy theorem

What is special about a dc circuit ?