1. Explain with a diagram how periscope is useful to the navigators in a submarine.
2. Explain why the image in a mirror is called a ‘Virtual Image’.

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

trig 15.3 cos

ok

explanation:

heats surface water up