Chapter 1: Physical Quantities, Units and Measurements

List the base quantities, their SI units and their symbols.

length (metre/m), mass (kilogram/kg), time (second/s), electric current (ampere/a), temperature (kelvin/K), amount of substance (mole/mol)

List the factor and symbol of prefix tera-

10^12, T

List the factor and symbol of prefix giga-

10^9, G

List the factor and symbol of prefix mega-

10^6, M

List the factor and symbol of prefix kilo-

10^3, k

List the factor and symbol of prefix deci-

10^-1, d

List the factor and symbol of prefix centi

10^-2, c

List the factor and symbol of prefix milli-

10^-3, m

List the factor and symbol of prefix micro-

10^-6, μ

List the factor and symbol of prefix nano-

10^-9, n

List the apparatus used to measure length and its accuracy in brackets in mm.

Micrometer screw gauge (0.01mm), vernier calipers (0.01mm), metre rule (1mm) , measuring tape (1mm)

List down 5 scalar quantities.

distance, speed, mass, energy, time

List down 5 vector quantities

displacement, velocity, acceleration, force, weight

State the difference between a vector quantity and scalar quantity,

A vector quantity has both magnitude and direction, while a scalar quantity only has magnitude.

State two ways to improve the accuracy of a reading when measuring the diameter of a wire.

* Measure different parts of the wire to get a different diameter
* Measure different diameters of the same part of wire and calculate the average diameter

What are three disadvantages of a micrometer screw gauge?

* Not able to measure large readings
* Does not have inner jaw or tail to measure internal diameter or depth of an object unlike vernier calipers

How does placing wooden blocks at both ends of an object on a ruler eliminate parallax error?

Wooden blocks are directly in contact with the scale

Why is it recommended to measure the diameter of 5 of the same object than 1?

If there is a slight difference in the diameter of each object, taking the average diameter of 5 objects is more accurate than measuring the diameter of one only.

How does the distance a pendulum bob is displaced from affect the time taken for the bob for one oscillation?

No effect