1.the student measures the mass of a piece of metal. its mass is 146g. (a) the volume of the piece of metal is 20cmcube. calculate the density of the metal .
(b) state the unit.

7.3 g/cubic cm

Explanation:

You divide the mass by the volume to calculate the density of the metal.

146g ÷ 20cm³ = 7.3g/cm³

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.