1. What’s the Unit?

2. Most physical quantities have units. You need to know the SI unit for each quantity you use.

3. When we say physical “quantities”, we mean things like time, distance, area, density, etc.

4. When we say “units” we mean the standard amounts of each quantity. The standard amounts of time are seconds, minutes, etc…the units.

5. When we say SI we mean the main version of the metric system used in science. SI stands for International System. Another name for the SI is the “mks system”. mks stands for meters, kilograms, seconds.

6. You learn many units just by using them a lot. The ones you don’t know well you should memorize.

7. Here we go:

8. What’s the SI unit for distance? meter

9. Mass…what’s the SI unit? kilogram

10. The SI unit for time? second

11. Units for distance, mass, and time? meters, kilograms, and seconds

12. SI units for length? meter For width? meter For height? meter

13. For breadth, and depth? meter Any distance, in any direction, has meters as the SI unit.

14. displacement? meter

15. speed? meters per second velocity? meters per second

16. Acceleration? meters per second per second or, meters per second squared

17. Force? newtons

18. Friction force? newtons Coefficient of friction?? No units

19. Elastic force (spring force)? newtons Spring constant? newtons per meter

20. Tension force? newtons

21. Electric force? newtons

22. Gravitational force? newtons

23. Weight force? newtons. And “weight” is the same thing as gravitational force.

24. Energy? joules

25. Kinetic Energy? joules

26. Gravitational Potential Energy? joules

27. Elastic Potential Energy? joules

28. Work Energy? joules

29. Momentum? kilograms x meters per second

30. Impulse? kilograms x meters per second or, newtons x seconds

31. Electric Charge? coulombs

32. Electric Field? newtons per coulomb.

33. Magnetic Field? teslas.

34. Temperature? kelvin.

35. Electric Potential (a.k.a.Voltage)? volts

36. Electric Current? amperes (amps)

37. Electrical Resistance? ohms

38. Resistivity? ohms x meters

39. Frequency? hertz

40. Period? seconds

41. Power? watts

42. Area? meters squared, or square meters

43. Distance Displacement Height Length ______

44. Distance Displacement Height Length meters

45. Gravitational force (a.k.a.weight) Elastic force Friction force Normal force Tension force _______

46. Gravitational force (a.k.a.weight) Elastic force Friction force Normal force Tension force newtons

47. Kinetic energy Elastic potential energy Gravitational potential energy Internal energy Work _____

48. Kinetic energy Elastic potential energy Gravitational potential energy Internal energy Work joules

49. Momentum Impulse ________________________, or _____________.

50. Momentum Impulse Kilogram x meters per second, or newton seconds.

51. acceleration _________________________ or _____________________

52. acceleration meters per second per second or meters per second squared

53. That’s all for “What’s the Unit”.