Problem Set 1.3: Math Review: Formulas

1. Solve each formula for the variable indicated.

a) A = lw, w b) A = ¹/₂ bh, h

c) g = a + w, a d) P = s – e, s

e) v = u + at, u f) W = R + Ht, t

2. Solve for the variable indicated.

a) , a

b) , s

c) , E

d) , a

e) n

f) , t

3. The formula for the circumference of a circle is C = pd, where p = 3.14.

a) Solve the formula for d.

b) Canada’s largest tree is a Douglas fir on Vancouver Island. Its circumference is 12.54 m. Use the formula for find the diameter of Canada’s largest tree.

4. The perimeter of a rectangle is

a) Solve the formula for w.

b) What is the width of a rectangle that has perimeter of 48 cm and a length of 18 cm? 6 cm

5. Use the density formula to find the mass of 55.2 cm³ of aluminum (d_Al = 2.70 g/cm³) and 82.3 cm³ of mercury (d_Hg = 11.4 g/cm³). Mass of aluminum = 149 g; mass of mercury is 938 g

6. The average cost, A, of producing n stereos sets is given by the formula:

rearrange to 750 stereos

How many stereo sets would have to be produced for the average cost to be $80?

7. The temperature below the Earth’s surface, T, in degrees Celsius, is given by the formula: T=10d + 20, where d is the depth in kilometers.

a) The deepest hole in the Earth is a test-drilling hole in Russia. At the bottom of the hole the temperature is expected to reach 170’C. Estimate the depth of the drilling. 15 km

b) Estimate the depth of a mine in which the temperature is 420˚C. 40. km