A graduated cylinder is filled with 20ml of water. Then, an 8g marble is dropped into the cylinder, causing the volume to change to 24ml. What is the density of the marble?

The density of the marble is 2,000 kg/m³

Step-by-step explanation:

The given parameters for finding the density of the marble are;

The volume of water in the graduated cylinder, v₁ = 20 ml

The mass of the marble dropped into the graduated cylinder, m = 8 g

The new volume of the cylinder after the 8 g marble is dropped into the cylinder, v₂ = 24 ml

Therefore, the volume of the marble, v = v₂ - v₁

Substituting the known values gives;

The volume of the marble, v = 24 ml - 20 ml = 4 ml

Density, ρ = Mass, m/(Volume, v), the units of density is kg/m³

Therefore, the density of the marble, , is given as follows;

= m/v = (8 g)/(4 ml) = 2 g/ml

1 g/ml = 1 kg/l = 1,000 kg/m³

∴ = 2 kg/l = 2,000 kg/m³.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles