A45.0-kg girl is standing on a 147-kg plank. the plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. the girl begins to walk along the plank at a constant velocity of 1.53 m/s to the right relative to the plank. (let the direction the girl is moving in be positive. indicate the direction with the sign of your answer.)

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.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

Which describes an object in projectile motion? check all that apply. a.gravity acts to pull the object downb. the object moves in a straight path. c.the forward velocity of the object is 0 m/s. d.the object’s inertia carries it forward. e.the path of the object is curved.