8. The density (D) is related to the mass (M) and the volume (V) of a substance by the formula
D=m/v

(a) Transpose the equation to make M the subject and hence find the mass when the volume is 12 and the density is 7. (2)

(b) Transpose the equation to make V the subject and hence find the volume when the mass is 3.4 and the density is 1.8.

Respuesta :

Answer:

M = 84

V = 1.89

Step-by-step explanation:

We are given the formula:

D = M/V

Where D is the density, M is the mass, and V is the volume of a substance.

(a) We'll use transposition to make M the subject of the equation.

To isolate M, we need to multiply by V on both sides of the equation:

D*V = M/V * V

The right side of the equation simplifies:

D*V = M

Now we swap sides:

M = D*V

Substituting the given values of V=12 and D=7:

M = 7 * 12 = 84

M = 84

(b) Now we must make V the subject of the equation:

D = M/V

Again, we multiply by V:

D * V = M

Now divide by D:

V = M/D

Substitute M=3.4, D=1.8:

V = 3.4/1.8

V = 1.89