physical quantities (physics)

Question 1

What is physics?

Answer 1

Physics is the study of matter and energy and the interaction between the two.

Question 2

What are the base quantities in physics?

Answer 2

Base quantities include length, mass, time, electric current, temperature, and amount of substance.

Question 3

What is the SI unit for length?

Answer 3

Metre (m)

Question 4

What is the SI unit for mass?

Answer 4

Kilograms (kg)

Question 5

What is the SI unit for time?

Answer 5

Seconds (s)

Question 6

What is the SI unit for electric current?

Answer 6

Ampere (A)

Question 7

What is the SI unit for temperature?

Answer 7

Kelvin (K)

Question 8

What is the SI unit for amount of substance?

Answer 8

Mole (mol)

Question 9

What is the prefix for 10^12?

Answer 9

Tetra- (T)

Question 10

What is the prefix for 10^9?

Answer 10

Giga- (G)

Question 11

What is the prefix for 10^6?

Answer 11

Mega- (M)

Question 12

What is the prefix for 10^3?

Answer 12

Kilo- (k)

Question 13

What is the prefix for 10^-1?

Answer 13

Deci- (d)

Question 14

What is the prefix for 10^-2?

Answer 14

Centi- (c)

Question 15

What is the prefix for 10^-3?

Answer 15

Milli- (m)

Question 16

What is the prefix for 10^-6?

Answer 16

Micro- (µ)

Question 17

What is the prefix for 10^-9?

Answer 17

Nano- (n)

Question 18

What affects accuracy in measurements?

Answer 18

Random error and systematic error.

Question 19

How can random error be minimized?

Answer 19

By averaging a large number of readings and discarding anomalous results before averaging.

Question 20

What is systematic error?

Answer 20

An error that consistently underestimates or overestimates measurements.

Question 21

Record length using a measuring tape to?

Answer 21

Record measurements to the nearest 0.1 cm (1 mm).

Question 22

record length using a metre rule to?

Answer 22

Record measurements to the nearest 0.1 cm (1 mm).

Question 23

Record length using digital calipers to?

Answer 23

Record measurements to the nearest 0.01 cm (0.1 mm).

Question 24

Record length using a digital micrometer screw gauge to?

Answer 24

Record measurements to the nearest 0.001 cm (0.01 mm).

Question 25

How to accurately measure length using measuring tapes and metre rules?

Answer 25

Keep eye perpendicular to mark on scale to avoid parallax error.

Question 26

What should be avoided when using a metre rule?

Answer 26

Avoid using the zero mark as the start point due to wear and tear.

Question 27

How to accurately measure length using a digital micrometer screw gauge?

Answer 27

Turn the thimble until the anvil and spindle gently touch the object and turn the ratchet until it clicks once to prevent overtightening

Question 28

What is the period of a pendelum

Answer 28

Amt of time it takes to complete one oscillation

Question 29

What is a source of error in measuring short durations of time

Answer 29

human reaction time

Question 30

How to improve accuracy when determining source of error

Answer 30

take readings of ___ and calculate average. Gives a smaller proportion of same human reaction time in the final result

Question 31

Two advantages of digital micrometer screw gauge over digital caliper

Answer 31

More precise Ratchet prevents overtightening

Question 32

3 ways to improve accuracy of results when using a digital caliper

Answer 32

Close the jaws and reset to 0 before taking measurements Close the jaws so that they gently touch each other --> prevents overtightening Ensure object is parallel to digital calipers when measuring length

Question 33

Two adv of using digital calipers > ruler

Answer 33

More precise measurement as precision up to 0.1mm while ruler only 1mm Jaws ensure closing ard widest point of round object, making measuring the diameter easier

Question 34

Other than air being a poor conductor of heat, explain why food can be kept cold longer if the wall contains air between the double layer

Answer 34

Trapped air reduces air flow that is needed for convection of heat from surroundings to the food

Question 35

Explain why the dull black surface is not considered a better radiator of heat than a silver surface for heat transferred from lamp to plates

Answer 35

Net heat ransfer is from the lamp to the plates

Question 36

Explain why temp of a heat sink remains constant after some time even though the electrical component is continuously producing heat

Answer 36

Rate of heat gain from the electrical component equals the rate of heat loss to the surroundings

Question 37

Gradient

Answer 37

Identify two other points on the graph. Shld be at least ¾ line away from each other Write coordinates down to the correct d.p. (1/2 the smallest square) Draw good triangle (only mark data points with x)

Question 38

State r’ship between A and B2

Answer 38

As A increases, B2 increases linearly