Unit 1: Physical Quantities & Units

Question 1

Physical quantity:

Answer 1

A measured quantity that consists of a numerical magnitude and a unit

Question 2

5 SI base units:

Answer 2

• Kilogram
• Meter
• Second
• Kelvin
• Mol

Question 3

Random errors:

Answer 3

Errors that cause unpredictable fluctuations in an instruments readings as a result of uncontrollable factors - affecting the precision of measurements taken, causing a wider spread of results about the mean value.

Question 4

How to reduce random error:

Answer 4

Repeat measurements several times and calculate an average.

Question 5

Systematic errors:

Answer 5

Errors that are from the use of faulty instruments/flaws from experimental method - affects accuracy of all readings obtained.

Question 6

How to reduce systematic errors:

Answer 6

Instruments should be recalibrated/technique adjusted.

Question 7

Precision:

Answer 7

How close the measured values are to each other.

Question 8

Accuracy:

Answer 8

How close the measured value is to the true value.

Question 9

Distance:

Answer 9

Measure of how far an object travels.

Question 10

Displacement:

Answer 10

Measure of how far something is from its starting position, along with its direction.

Question 11

Speed:

Answer 11

The distance an object travels every second.

Question 12

Velocity:

Answer 12

A moving objects speed and also describes direction of the velocity.

Question 13

Acceleration:

Answer 13

The rate change of velocity.