Which of these are physical quantities?
a. time
b. energy
c. seconds
d. kilometers
e. volume
Question 2
In the leftmost photo below, an instructor demonstrates that a standard two-by-four on a curved dish can be rotated by the attractive force of a charged rod. The two-by-four is affected by the charged rod of the same way as:
a. the metal ball in the figure 20-3.
b. the insulating object in the figure at above right.
c. neither of the two; a different mechanism is involved since the two-by-four is so massive.