Now, in the Tracker tool, add kinetic energy, KE, and potential energy, PE, to your table. (Click on Table, then check KE and PE in the Table Columns dialog.) Also, adapt the two graphs to show kinetic energy and potential energy vs. time. (Click on the
vertical axis labels; from the pop-up menu, select KE or PE.)
Step forward through the video a frame at a time, tracking the process in the table and on the two graphs. Based on your
observations, what can you say about your predictions in Part A and Part B concerning the potential and kinetic energy?

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

no. dot product   =0 when vecs at right angles

volts times amps 6 x 0.5 3w

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.