Mass and Weight | Waec Physics

Mass and Weight

1. Mass is the amount of matter in a body.
2. Weight is the gravitational force acting on an object's mass.
3. Mass is a scalar quantity and has only magnitude.
4. Weight is a vector quantity and has both magnitude and direction.
5. Weight depends on the gravitational field strength, while mass remains constant.
6. The formula for weight is $W = mg$, where $m$ is mass and $g$ is acceleration due to gravity.
7. On Earth, $g$ is approximately $9.8m/s^2$, but it varies with location.
8. Mass is measured in kilograms (kg) in the SI system.
9. Weight is measured in newtons (N), with $1N = 1kg \cdot m/s^2$.
10. An object’s weight changes on different planets due to variations in gravitational pull.
    paragraph

Use of Lever Balance and Chemical/Beam Balance to Measure Mass

11. A lever balance measures mass by comparing the object’s mass with standard weights.
12. Lever balances operate on the principle of moments, ensuring equilibrium.
13. Lever balances are commonly used in markets and for simple mass measurements.
14. A chemical balance measures small masses with high precision, often used in laboratories.
15. The chemical balance uses a beam and scale pans to measure mass.
16. Proper calibration of balances ensures accurate mass measurements.
17. A beam balance measures mass by achieving balance between two pans.
18. Beam balances are often used in educational demonstrations to illustrate the concept of mass.
19. Balances rely on gravitational force to compare masses indirectly.
20. Both lever and beam balances require careful handling to maintain accuracy.
    paragraph

Use of Spring Balance to Measure Weight

21. A spring balance measures weight based on the principle of Hooke’s Law.
22. Hooke’s Law states that the extension of a spring is proportional to the force applied, $F = kx$.
23. Spring balances directly measure the force (weight) acting on the object.
24. The scale of a spring balance is calibrated in newtons (N).
25. A spring balance stretches as the gravitational force acts on the object.
26. Weight readings from a spring balance vary with changes in gravitational strength.
27. Spring balances are portable and commonly used for quick weight measurements.
28. They are less accurate than balances for measuring mass but useful for weight comparisons.
29. Calibration of the spring ensures reliable measurements.
30. Misuse or overstretching the spring can lead to inaccurate readings.
    paragraph

Distinction Between Mass and Weight

31. Mass is an intrinsic property of an object and does not change with location.
32. Weight depends on the gravitational pull and varies with location.
33. Mass is measured in kilograms (kg), while weight is measured in newtons (N).
34. On the Moon, mass remains constant, but weight is about $1/6$ of its value on Earth.
35. Mass affects inertia, which determines an object's resistance to changes in motion.
36. Weight is the force acting due to gravity and determines how heavy an object feels.
37. A balance measures mass, whereas a spring balance measures weight.
38. Mass is constant for a given object, but weight changes with gravitational field strength.
39. In calculations, mass is used to determine momentum and energy, while weight is used for forces.
40. Understanding the distinction is critical in scientific and engineering applications.
    paragraph

Kilogram (kg) as Unit of Mass and Newton (N) as Unit of Weight

41. The kilogram (kg) is the SI base unit for mass.
42. The kilogram is defined based on the Planck constant in modern physics.
43. The newton (N) is the SI derived unit for weight and force.
44. One newton is defined as the force required to accelerate $1kg$ of mass by $1m/s^2$.
45. Mass is measured using balances, which are unaffected by gravity.
46. Weight is calculated using the equation $W = mg$ and depends on $g$.
47. The relationship between mass and weight is linear: as mass increases, weight increases proportionally.
48. In space, where $g = 0$, objects have mass but no weight.
49. The distinction between kg and N prevents confusion in physics and engineering.
50. Accurate use of units ensures clear communication and consistency in scientific work.

I recommend you check my Post on the following: