Ship a is located 4.0 km north and 2.5 km east of ship b. ship a has a velocity of 22 km/h toward the south, and ship b has a velocity of 40 km/h in a direction 37° north of east.
(a) what is the velocity of a relative to b in unit-vector notation with ˆi toward the east?
(b) write an expression (in terms of ˆi and ˆj) for the position of a relative to b as a function of t, where t 0 when the ships are in the positions described above.
(c) at what time is the separation between the ships least?
(d) what is that least separation?

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.

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above

Which lists correctly orders nuclear reactions from most radioactive waste generated to least waste generated within a given period of time? o a. radioactive decay, nuclear fission, nuclear fusion o b. radioactive decay, nuclear fusion, nuclear fission o c. nuclear fusion, nuclear fission, radioactive decay o d. nuclear fission, nuclear fusion, radioactive decay