AS Physics - Chapter 1

A flashcard deck for terms and definitions in Chapter 1 of AS Physics

What defines a physical quantity?

A physical quantity must consist of a numerical magnitude and a unit.

How many significant figure(s) are reasonable estimates expected to be in?

One (1) S.F.

What are the five (5) SI base quantities for Physics?

1. Mass (measured in kilograms; represented by ‘m’)

2. Length (measured in meters; represented by lower-case ‘L’)

3. Time (measured in seconds; represented by ‘t’)

4. Electric Current (measured in amperes, represented by ‘I’)

5. Thermodynamic Temperature (measured in Kelvins; represented by ‘T’)

What are the five (5) SI base units?

1. Mass: kg

2. Length: m

3. Time: s

4. Electric Current: A

5. Thermodynamic Temperature: K

What are derived units?

Products OR quotients of SI base units.

{Derived Unit}
What is the formula and unit for velocity (v)?

Formula: Δs / Δt (change in displacement divided by change in time)
Unit: ms^-1

{Derived Unit}
What is the formula and unit for acceleration (a)?

Formula: Δv / Δt (change in velocity divided by change in time)
Unit: ms^-2

{Derived Unit}
What is the formula and unit for force (F)?

Formula: m × a (mass multiplied by acceleration)
Unit: kgms^-2

{Derived Unit}
What is the formula and unit for momentum (p)?

Formula: m × v (mass multiplied by velocity)
Unit: kgms^-1

{Derived Unit}
What is the formula and unit for work (w or W)?

Formula: F × s (force multiplied by distance)
Unit: kgm²s^-2

{Derived Unit}
What is the formula and unit for density (ρ; rho)?

Formula: m / v (mass divided by volume)
Unit: kgm^-3

{Derived Unit}
What is the formula and unit of pressure (p)?

Formula: F / A (force divided by area)
Unit: kgm^-1s^-2 (unit of area: m²)

What will the homogeneity of physical quantities look like in an addition or subtraction equation?

Each term on both sides of the equals (=) sign will have the same unit.

What will the homogeneity of physical quantities look like in a multiplication or division equation?

The units of the terms on the left side of the equation will be equal (=) to the units of the terms on the right side of the equation.

What do prefixes in Physics indicate?

They indicate decimal multiples and sub-multiples.

What multiple of 10 does the prefix deci (d) stand for?

10^-1

What multiple of 10 does the prefix centi (c) stand for?

10^-2

What multiple of 10 does the prefix milli (m) stand for?

10^-3

What multiple of 10 does the prefix micro (u) stand for?

10^-6

What multiple of 10 does the prefix nano (n) stand for?

10^-9

What multiple of 10 does the prefix pico (p) stand for?

10^-12

What multiple of 10 does the prefix kilo (k) stand for?

10³

What multiple of 10 does the prefix mega (M) stand for?

10⁶

What multiple of 10 does the prefix giga (G) stand for?

10⁹

What multiple of 10 does the prefix tera (T) stand for?

10¹²

What effect do systematic and random errors have on data values?

They can cause a reading to deviate from its true value.

What is the effect of a systematic error?

The readings are larger OR smaller than the true reading by a constant amount.

What are the two potential sources of a systematic error?

1. Zero error

2. Wrongly calibrated scale

What are the two improvements, respectively, for the two possible sources of a systematic error?

1. Check for a zero error on your measuring instrument and account for the value.

2. Recalibrate the measuring instrument.

What is the effect of a random error?

The readings are scattered about the true reading.

What are the two + one potential source(s) of a random error?

1. Readings of the instrument are taken from different angles.

2. The student is wrongly estimating the values of the divisions in the measuring instrument.

3. *There is variation due to external conditions such as a change - or lack thereof - in temperature or pressure or wind draft.

What is the improvement for the possible sources of a random error?

1. Repeat the measurements by n times, usually n = 10, and find the average.

   a) For a circular wire, take several readings along the length of the wire and then find the average.
   
   b) For a non-circular wire, take several readings around the wire and then find the average.

What is a intercept (x and y) indicator that your graph has a systematic error?

If the graph has either an x- or y-intercept, it has systematic errors.

Is there a systematic error if the graphs peak/average value aligns with the true value (X₀)?

No, if it’s aligned with the true value (X₀), there is no systematic error.

Is there a large amount of random error if the range of the graph is wider?

Yes, a larger range (with a flatter peak) indicates more random error.