Ireland · Year 9 · Practice Sheet 45

1. 1.

   A wave has frequency 577 Hz and wavelength 3.47 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
2. 2.

   A device runs at 49 V drawing 3.3 A. Find its power consumption.

   Formula:Electrical Power

   $P = V I$

   View formula →
3. 3.

   A car travels 630 km in 6 hours. Find its average speed.

   Formula:Speed

   $v = \dfrac{d}{t}$

   View formula →
4. 4.

   €3,100 is invested at 4% compound interest per annum for 4 years. Find the final amount (to 2 d.p.).

   Formula:Compound Interest

   $A = P\left(1 + \dfrac{r}{100}\right)^{t}$

   View formula →
5. 5.

   An object has mass 333.7 g and volume 47 cm³. Find its density.

   Formula:Density

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

   View formula →
6. 6.

   A car travels 78 km in 2 hours. Find its average speed.

   Formula:Speed

   $v = \dfrac{d}{t}$

   View formula →
7. 7.

   A train moves at 36 km/h for 4.7 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
8. 8.

   €80 is shared in the ratio 3 : 5. Find each share.

   Formula:Dividing in a Ratio

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

   View formula →
9. 9.

   A train moves at 42 km/h for 5.2 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
10. 10.

    €256 is shared in the ratio 3 : 5. Find each share.

    Formula:Dividing in a Ratio

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

    View formula →
11. 11.

    A device runs at 184 V drawing 6.6 A. Find its power consumption.

    Formula:Electrical Power

    $P = V I$

    View formula →
12. 12.

    A car travels 188 km in 4 hours. Find its average speed.

    Formula:Speed

    $v = \dfrac{d}{t}$

    View formula →
13. 13.

    A current of 7 A flows through a 25 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
14. 14.

    A value changes from 166 to 243. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

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

    View formula →
15. 15.

    €1,400 is invested at 3% compound interest per annum for 3 years. Find the final amount (to 2 d.p.).

    Formula:Compound Interest

    $A = P\left(1 + \dfrac{r}{100}\right)^{t}$

    View formula →
16. 16.

    Find the momentum of a 35 kg object moving at 25 m/s.

    Formula:Momentum

    $p = mv$

    View formula →
17. 17.

    Find the force needed to accelerate a 3 kg mass at 8.2 m/s².

    Formula:Newton's Second Law

    $F = ma$

    View formula →
18. 18.

    €4,800 is invested at 5% simple interest per year for 5 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
19. 19.

    A bag has 21 equally likely marbles, of which 6 are red. Find the probability of drawing a red marble (to 3 d.p.).

    Formula:Simple Probability

    $P(E) = \dfrac{\text{favourable}}{\text{total}}$

    View formula →
20. 20.

    A force of 29 N moves an object 15 m in the direction of the force. Find the work done.

    Formula:Work Done

    $W = F d$

    View formula →

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