Ignoring reflection at the air-water boundary, if the amplitude of a f=1.1ghzf=1.1ghz incident wave in air is v0=15v/mv0=15v/m at the water surface, determine the depth that make the electric field down to vmin=2μv/vmin=2μv/my. water has μr=1μr=1 and at 1.1ghz 1.1 ghz, εr=70εr=70 and σ=1.5s/mσ=1.5s/m.

no. dot product   =0 when vecs at right angles

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j