Ch 1 Physical Quantities and Units#

Question 1

All physical quantities consist of __________ and ___________.

Answer 1

numerical magnitude and unit

Question 2

What are the 6 base quantities?

Answer 2

mass, length, time, current, temperature and amount of substance

Question 3

What is the SI unit of mass?

Answer 3

kilogram (kg)

Question 4

What is the SI unit of length?

Answer 4

meter (m)

Question 5

What is the SI unit of time?

Answer 5

second (s)

Question 6

What is the SI unit of current?

Answer 6

ampere (A)

Question 7

What is the SI unit of temperature?

Answer 7

kelvin (K)

Question 8

What is the SI unit of speed?

Answer 8

meters per second (m/s)

Question 9

What is the SI unit of acceleration?

Answer 9

meters per square second (m/s2)

Question 10

What is the SI unit of density?

Answer 10

kilogram per cubic meter (kg/m3)

Question 11

What is a scalar quantity?

Answer 11

A quantity with only magnitude.

Question 12

What is a vector quantity?

Answer 12

A quantity with both magnitude and direction.

Question 13

Convert 0.001 m to mm.

What does the prefix ‘m’ represents?

Answer 13

1 mm

Question 14

Convert 300 g to kg.

What does the prefix ‘k’ represents?

Answer 14

0.3 kg

Question 15

Convert 0.00001 m to µm.

What does the prefix ‘µ’ represents?

Answer 15

10 µm

Question 16

Convert 200 000 W to MW.

What does the prefix ‘M’ represents?

Answer 16

0.2 MW

Question 17

Convert 20 000 000 J to GJ.

What does the prefix ‘G’ represents?

Answer 17

0.02 GJ

Question 18

Convert this number to standard form:
0.003

example of a standard form number

Stardard form is a way of writing numbers in which a number between 1 to 10 is multiplied by an appropiate power of 10.
See picture for an example.

Answer 18

3.0 x 10^-3

Question 19

Give one example of a vector quantity.

Answer 19

Any of the following is correct:

velocity, acceleration, force, displacement, weight.

This list is not exhaustive.

Question 20

Give one example of a scalar quantity.

Answer 20

Any of the following is correct:

speed, distance, time, mass, current, voltage, resistance etc.

This list is not exhaustive.

Question 21

What are the 4 instruments used to measure length?

Answer 21

1) meter rule
2) measuring tape
3) digital caliper
4) digital micrometer

Each instrument has its own precision ( the smallest unit the instrument can measure) and can to use to measure a wide variety of length.

Question 22

What is the smallest division of a measuring tape?

Answer 22

0.1 cm

Question 23

What is the smallest division of a meter rule?

Answer 23

0.1 cm

Question 24

What is the smallest division of a digital calipers?

Answer 24

0.001 cm

Question 25

What is the smallest division of a digital micrometer?

Answer 25

0.001 mm

Question 26

What is parallax error?

Answer 26

An error when the eye is not positioned in a line of sight perpendicular to the measurement readings.

parallax error of ruler

Question 27

What are the two types of observational errors?

Answer 27

random error and systematic error

Question 28

What is a random error?

Answer 28

Random error varies unpredicatbly for different measurements.

Question 29

What is a systematic error?

Answer 29

Systematic error is constant and not random. The error value is always the same for every measurement.

Question 30

What is an oscillation?

Answer 30

A complete to-and-fro motion.

Question 31

What does it mean by ‘the period of simple pendulum’?

Answer 31

The time taken by the pendulum to complete one oscillation.