Question

For this question, let ma and mb represent masses; l1, l2, l3, and x represent lengths; and t1 and t2 represent times.

A mass density is defined as a mass per unit volume and volume has the dimensions of [length] 3.

Which of the following could be mass densities?
ma / [(l1)(l2){x / t1} t2]
A: True B: False

[(mb)(x) / [(l1)2(l2)2]
A: True B: False

[{ma}{mb}] / [(l1)(l2)(l3)]
A: True B: False

[mb2] / [(l1)2)(l2)2]
A: True B: False

Three of the above could represent mass densities.
A: True B: False

Answer 1

To me, none of them could be mass densities

Answer 2

sorry about the format- if a symbol has a 2 next to it, it is squared

Answer 3

for this question... you have convert all your unit into mass, length and time and then you have to see which of the options has the same units as density

Answer 4

maybe the second one since its a mass x length/ length^4

Answer 5

which would mean mass / length^3?

Answer 6

but what about the ones that have mass^2?

Answer 7

yes.... which is the same as mass density

Answer 8

those are wrong since mass density is mL^(-3)

Answer 9

so its false, true, false false false?

Answer 10

or is the first oen ok since time cancels out?

Answer 11

no... check all of them and see if the mass cancels out to give m^1... simplify each expression. You should get the final result as (mass)^1 *(length)^(-3)

Answer 12

I only got that for the first two then

Answer 13

thats your answer

Answer 14

great! thanks!

Answer 15

np