30a) What is the magnitude of the electric field at point p from one of the 3 nC charges? Remember cm + m.
The E3 from the 3 nC charges will have (x, y) components.
Because there are 23 n charges, one of these components (x or
y) will cancel out, and the other components add together.
b) Erase each wrong answer (x or y), leaving the correct answer.
x or y will components cancel
x or y components will remain
c) Calculate the value of the remaining component of E3 from 1 of
the 3 nc charge.
d) What is the magnitude and direction of the net electric field at
P from both 3 nC charges? Remember symmetry and remaining
components (x or y).
e) Now determine the magnitude and direction of the electric field
at P from the -2 nc charge.
f) What is the magnitude and direc-otion of the net electric field at
P from all the charges?

During physical science, ms. greene challenged her students to produce an energy transformation. james and jill wrapped a 4-inch nail with a coil of fifty turns of wire. they connected one end of the coil to one terminal of a knife switch. they connected the other terminal of the knife switch to the battery. finally, they connected the end of the coil to the other terminal of the battery. james held the tip of a 1-inch nail near the flat end of the 4-inch nail. jill closed the knife switch quickly and then opened it. the 1-inch nail was pulled toward the 4-inch nail. what is the best explanation of why the nail moved? a) electrical energy was converted to mechanical energy in the 1-inch nail. b) the 4-inch nail became an electromagnet and the magnetic force attracted the 1-inch nail. c) the electric current in the 4-inch nail was converted to mechanical energy in the 1-inch nail. d) the 4-inch nail had a positive charge and the 1-inch nail had a negative charge. opposites attracted.

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?