A 0.25 ball is thrown with the speed of v=4.5m/s at a resting stick that can rotate around one end at the axis O. The ball hits the stick at r=0.75 m from O. What is the angular momentum of the ball about the axis O before hitting the stick ?

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.

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

What do you think car designers do if the damage caused by a crash test is too severe?