An air puck of mass 0.034 kg is tied to a string and allowed to revolve in a circle of radius 1.7m on a frictionless horizontal surface. The other end of the string passes through a hole in the center of the surface, and a mass of 2.5 kg is tied to it, as shown. The suspended mass remains in equilibrium while the puck
revolves on the surface.
1.7 m
2.5 kg
0.034 kg
What is the magnitude of the force that
maintains circular motion acting on the puck?
The acceleration due to gravity is 9.81 m/s
2
.
Answer in units of N.

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

Asmall, positively charged ball is moved close to a large, positively charged ball. which describes how the small ball likely responds when it is released? it will move toward the large ball because like charges repel. it will move toward the large ball because like charges attract. it will move away from the large ball because like charges repel. it will move away from the large ball because like charges attract.

Suppose that an electromagnetic wave which is linearly polarized along the x−axis is propagating in vacuum along the z−axis. the wave is incident on a conductor which is placed at z > 0 region of the space. the conductor has conductivity σ, magnetic permeability µ and electric permittivity ε. (a) find the characteristic time for the free charge density which dissipates at the conductor. (b) write the maxwell equations and derive the wave equation for a plane wave propagating in a conductor. (c) find the attenuation distance at which the incident amplitude reduces to e ^−1 of its initial value. (d) find the electric and magnetic fields inside the conductor. 8 (e) find the power loss per area of the incident electromagnetic wave at the surface of conductor.