Brazil · Ano 9 · Practice Sheet 20

1. 1.

   A wave has frequency 748 Hz and wavelength 2.62 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
2. 2.

   A force of 307 N acts on an area of 2.3 m². Find the pressure.

   Formula:Pressure

   $P = \dfrac{F}{A}$

   View formula →
3. 3.

   A wave has frequency 266 Hz and wavelength 1.28 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
4. 4.

   A circle has a radius of 11 cm. Find its area. (Use π ≈ 3.14159)

   Formula:Area of a Circle

   $A = \pi r^2$

   View formula →
5. 5.

   A train moves at 63 km/h for 2.4 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
6. 6.

   A cylinder has radius 2 cm and height 11 cm. Find its volume. (π ≈ 3.14159)

   Formula:Volume of a Cylinder

   $V = \pi r^2 h$

   View formula →
7. 7.

   Find the gravitational potential energy of a 50 kg object raised 23 m. (g = 9.8 m/s²)

   Formula:Gravitational Potential Energy

   $PE = mgh$

   View formula →
8. 8.

   R$ 4,000 is invested at 3% simple interest per year for 3 years. Find the interest earned.

   Formula:Simple Interest

   $I = \dfrac{P \times r \times t}{100}$

   View formula →
9. 9.

   A device runs at 222 V drawing 0.5 A. Find its power consumption.

   Formula:Electrical Power

   $P = V I$

   View formula →
10. 10.

    A value changes from 39 to 95. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

    $\%\,\text{change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$

    View formula →
11. 11.

    A cone has base radius 8 cm and height 24 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cone

    $V = \tfrac{1}{3} \pi r^2 h$

    View formula →
12. 12.

    A device runs at 228 V drawing 9.8 A. Find its power consumption.

    Formula:Electrical Power

    $P = V I$

    View formula →
13. 13.

    A value changes from 196 to 218. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

    $\%\,\text{change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$

    View formula →
14. 14.

    A right-angled triangle has legs of 8 cm and 18 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

    $c = \sqrt{a^2 + b^2}$

    View formula →
15. 15.

    R$ 2,400 is invested at 3% simple interest per year for 4 years. Find the interest earned.

    Formula:Simple Interest

    $I = \dfrac{P \times r \times t}{100}$

    View formula →
16. 16.

    A value changes from 110 to 34. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

    $\%\,\text{change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$

    View formula →
17. 17.

    R$ 240 is shared in the ratio 5 : 5. Find each share.

    Formula:Dividing in a Ratio

    $\text{share} = \dfrac{\text{part}}{\text{total parts}} \times T$

    View formula →
18. 18.

    A value changes from 57 to 98. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

    $\%\,\text{change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$

    View formula →
19. 19.

    A cone has base radius 8 cm and height 24 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cone

    $V = \tfrac{1}{3} \pi r^2 h$

    View formula →
20. 20.

    An object has mass 124.8 g and volume 26 cm³. Find its density.

    Formula:Density

    $\rho = \dfrac{m}{V}$

    View formula →

© FormulaWon — formulawon.app · Answers & step-by-step working available on the solutions sheet.