Awooden block slides down a ramp that is 12 meters long in 4 seconds. what was the average speed of the wooden block? \

a. 16 m/s

b. 3 m/s

c. 12 m/s

d. 48 m/s

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.

In a good thermo flask the main cause of heat loss is

Acircuit contain a 5-ohm,a3-ohm,and an 8-ohm resistor in series. what is the total resistance of the circuit