Ablock of mass 3 kg, which has an initial
speed of 4 m/s at time t = 0, slides on a
horizontal surface.
find the magnitude of the work that must
be done on the block to bring it to rest. answer in units of j if a constant friction force of magnitude 2 newtons is exerted on the block by the surface, find the magnitude of the acceleration of the block.
how far does the block slide before it comes to rest? units of m

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.

Slab pull” is a type of tectonic plate movement that occurs due to the forces of mantle convection and results in the subduction of the lithosphere true or false

Could we see a galaxy that is 20 billion light-years away?