15 Basic Physics Formulas With Questions

Basic Physics

Physics is all around us, from how we walk to how the planets move. One way to understand the world of physics is through formulas. These formulas help explain how different elements of the world work.

In this blog, we’ll cover 15 basic physics formulas and give examples of questions related to them. These formulas are useful for students at any level and are commonly used in school physics classes.

  1. Newton’s Second Law of Motion

    2. Formula:
    F=ma
    Where:

    • F = force (in newtons)
    • m = mass (in kilograms)
    • a = acceleration (in meters per second squared)


    Example Question:
    A car with a mass of 1,000 kg accelerates at 2 m/s². What is the force acting on the car?

    Answer:
    F=1,000×2=2,000 N

  2. Gravitational Force

    3. Formula:
    F=Gm1m2/r2
    Where:

    • F = gravitational force (in newtons)
    • G = gravitational constant (6.674×10−11 Nm2/kg2)
    • m1,m2 = masses (in kilograms)
    • r = distance between the masses (in meters)

    Example Question:
    What is the gravitational force between two objects with masses of 10 kg and 20 kg that are 5 meters apart?

    Answer:
    F= (6.674×10−11)×10×20/52 ≈5.3392×10−10 N

  3. Work Done

    4. Formula:
    W=Fd
    Where:

    • W = work (in joules)
    • F = force (in newtons)
    • d = distance (in meters)

    Example Question:
    A force of 50 N moves an object 10 meters. How much work is done?

    Answer:
    W=50×10=500 J

  4. Kinetic Energy

    5. Formula:
    KE=1/2mv2
     Where:

    • KE = kinetic energy (in joules)
    • m = mass (in kilograms)
    • v = velocity (in meters per second)

    Example Question:
    What is the kinetic energy of a 2 kg object moving at 3 m/s?

    Answer:
    KE=1/2×2×32=9 J

  5. Potential Energy

    6. Formula:
    PE=mgh
    Where:

    • PE = potential energy (in joules)
    • m = mass (in kilograms)
    • g = acceleration due to gravity (9.8 m/s)
    • h = height (in meters)

    Example Question:
    What is the potential energy of a 5 kg object that is 4 meters above the ground?

    Answer:
    PE=5×9.8×4=196 J

  6. Power

    7. Formula:
    P=Wt
    Where:

    • P = power (in watts)
    • W = work (in joules)
    • t = time (in seconds)

    Example Question:
    If 500 J of work is done in 10 seconds, what is the power?

    Answer:
    P=500/10=50 W

  7. Speed

    8. Formula:
    v=d/t
    Where:

    • v = speed (in meters per second)
    • d = distance (in meters)
    • t = time (in seconds)

    Example Question:
    If a car travels 100 meters in 5 seconds, what is its speed?

    Answer:
    v=100/5=20 m/s

  8. Acceleration

    9. Formula:
    a=Δv/t

    Where:

    • a = acceleration (in meters per second squared)
    • Δv = change in velocity (in meters per second)
    • t = time (in seconds)

    Example Question:
    If a car’s velocity changes from 0 m/s to 20 m/s in 4 seconds, what is its acceleration?

    Answer:
    a=20−0/4=5 m/s2

  9. Momentum

    10. Formula:
    p=mv
    Where:

    • p = momentum (in kilogram meters per second)
    • m = mass (in kilograms)
    • v = velocity (in meters per second)

    Example Question:
    What is the momentum of a 10 kg object moving at 3 m/s?

    Answer:
    p=10×3=30 kg m/s

  10. Ohm’s Law

    11. Formula:
    V=IR
    Where:

    • V = voltage (in volts)
    • I = current (in amperes)
    • R = resistance (in ohms)

    Example Question:
    What is the voltage across a circuit with a current of 2 A and resistance of 5 Ω?

    Answer:
    V=2×5=10 V

  11. Coulomb’s Law

    12. Formula:
    F=kq1q2/r2
     Where:

    • F = force (in newtons)
    • k = Coulomb’s constant (8.99×109 Nm2/C2)
    • q1,q2 = charges (in coulombs)
    • r = distance between charges (in meters)

    Example Question:
    What is the force between two charges of 1 C each, separated by 1 meter?

    Answer:
    F=(8.99×109)×1×1/12=8.99×109 N

  12. Frequency of a Wave

    13. Formula:
    f=1/T
    Where:

    • f = frequency (in hertz)
    • T = time period (in seconds)

    Example Question:
    What is the frequency of a wave with a time period of 0.5 seconds?

    Answer:
    f=1/0.5=2 Hz

  13. Density

    14. Formula:
    ρ=mV
    Where:

    • ρ = density (in kilograms per cubic meter)
    • m = mass (in kilograms)
    • V = volume (in cubic meters)

    Example Question:
    What is the density of an object with a mass of 10 kg and a volume of 2 m³?

    Answer:
    ρ=10/2=5 kg/m3

  14. Pressure

    15. Formula:
    P=F/A
    Where:

    • P = pressure (in pascals)
    • F = force (in newtons)
    • A = area (in square meters)

    Example Question:
    What is the pressure exerted by a force of 200 N on an area of 5 m²?

    Answer:
    P=200/5=40 Pa

  15. Wave Speed

    16. Formula:
    v=fλ
    Where:

    • v = wave speed (in meters per second)
    • f = frequency (in hertz)
    • λ = wavelength (in meters)

    Example Question:
    If a wave has a frequency of 10 Hz and a wavelength of 2 meters, what is its speed?

    Answer:
    v=10×2=20 m/s

Conclusion

These 15 basic physics formulas are the foundation for understanding more complex concepts. By practising these formulas and applying them to different problems, students can develop a strong grasp of physics.

At Centre Point School, students are taught such essential topics in a structured way, helping them build a solid foundation in physics while nurturing their curiosity for the subject.