3. The net force exerted by a woodpecker's head when its beak strikes a tree can be as large as 4.90 N, assuming that the bird's head has a mass of 50.0 g.
Assume that two different muscles pull the woodpecker's head forward and
downward, exerting a net force of 4.90 N. If the forces exerted by the muscles
are at right angles to each other and the muscle that pulls the woodpecker's
head downward exerts a force of 1.70 N, what is the magnitude of the force
exerted by the other muscle? Draw a free-body diagram showing the forces
acting on the woodpecker's head.

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.

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z

What are the similarities & differences between a thermistor and a light dependent resistor in physics?