Bangladesh · Class 12 · Practice Sheet 21

1. 1.

   Find the momentum of a 7 kg object moving at 23 m/s.

   Formula:Momentum

   $p = mv$

   View formula →
2. 2.

   A device runs at 169 V drawing 9.5 A. Find its power consumption.

   Formula:Electrical Power

   $P = V I$

   View formula →
3. 3.

   A wave has frequency 777 Hz and wavelength 3.5 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
4. 4.

   A current of 4.5 A flows through a 48 Ω resistor. Find the voltage across it.

   Formula:Ohm's Law

   $V = I R$

   View formula →
5. 5.

   A wave has frequency 728 Hz and wavelength 0.38 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
6. 6.

   A device runs at 126 V drawing 5.2 A. Find its power consumption.

   Formula:Electrical Power

   $P = V I$

   View formula →
7. 7.

   Find the momentum of a 50 kg object moving at 26 m/s.

   Formula:Momentum

   $p = mv$

   View formula →
8. 8.

   Two masses 2,200 kg and 660 kg are 12 m apart. Find the gravitational force between them. (G = 6.674×10⁻¹¹)

   Formula:Newton’s Law of Gravitation

   $F = G\dfrac{m_1 m_2}{r^2}$

   View formula →
9. 9.

   A wave has frequency 202 Hz and wavelength 3.92 m. Find its speed.

   Formula:Wave Speed

   $v = f\lambda$

   View formula →
10. 10.

    In a triangle, a = 8, b = 7 and the included angle C = 110°. Find side c (to 2 d.p.).

    Formula:Cosine Rule

    $c = \sqrt{a^2 + b^2 - 2ab\cos C}$

    View formula →
11. 11.

    A force of 231 N acts on an area of 8.5 m². Find the pressure.

    Formula:Pressure

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

    View formula →
12. 12.

    An object with initial velocity 3 m/s accelerates at 1.1 m/s² for 5 s. Find the distance travelled.

    Formula:Kinematics (s = ut + ½at²)

    $s = ut + \tfrac{1}{2}at^2$

    View formula →
13. 13.

    A population of 8,600 grows 3% per year. Find its size after 6 years (nearest whole number).

    Formula:Exponential Growth

    $N = N_0 (1 + r)^{t}$

    View formula →
14. 14.

    A current of 3.4 A flows through a 28 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
15. 15.

    Two masses 1,800 kg and 290 kg are 7 m apart. Find the gravitational force between them. (G = 6.674×10⁻¹¹)

    Formula:Newton’s Law of Gravitation

    $F = G\dfrac{m_1 m_2}{r^2}$

    View formula →
16. 16.

    Find the force needed to accelerate a 60 kg mass at 4.1 m/s².

    Formula:Newton's Second Law

    $F = ma$

    View formula →
17. 17.

    A device runs at 175 V drawing 0.8 A. Find its power consumption.

    Formula:Electrical Power

    $P = V I$

    View formula →
18. 18.

    A force of 35 N moves an object 8 m in the direction of the force. Find the work done.

    Formula:Work Done

    $W = F d$

    View formula →
19. 19.

    A wave has frequency 724 Hz and wavelength 2.48 m. Find its speed.

    Formula:Wave Speed

    $v = f\lambda$

    View formula →
20. 20.

    Find the population standard deviation of: 6, 5, 14, 19, 8 (to 2 d.p.).

    Formula:Standard Deviation (Population)

    $\sigma = \sqrt{\dfrac{\sum (x - \bar{x})^2}{n}}$

    View formula →

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