While you are sitting on a chair at the edge of a 1.2-m-deep swimming pool, your eyes are 1.5 m above the surface of the water. You see an acorn on the bottom of the pool at a 45 angle below the horizontal. What is the horizontal distance between you and the acorn?

Determine the critical height h of the water level that causes the concrete gravity dam to be on the verge of tipping over due to water pressure. the density of concrete is ρc = 2.40 mg/m3. suppose that hd = 38 m. hint: work the problem using a 1-m width of the dam.

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.

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?