1Base unit for mass?
Kilogram (kg)
2Base unit for length?
Metre (m)
3Base unit for time?
Seconds (s)
4Base unit for current?
Ampere (A)
5Base unit for amount of substance?
Mole (mol)
6Base unit for temperature?
Kelvin (K)
7What is the unit for charge, where does it derive from?
Coulomb, dervied from the ampere and second
8What is the unit for force, where is it derived from?
Newton, derived from the kilogram, metre and second
9What are the 6 base SI units?
Kelvin
Kilogram
Mole
Ampere
Second
Metre
10What is a scalar?
A quantity that has a magnitude
11What is a vector?
A quantity that has a magnitude and a direction
12Examples of Scalars?
Distance
Speed
Time
Temperature
Density
Mass
13Examples of vectors?
Displacement
Velocity
Acceleration
Force
Momentum
Magnetic field strength
14How are vectors graphically represented?
A straight line (length) with an arrow (direction)
15What is a resultant vector?
A combo of multiple vectors added or subtracted together
16What is the equation triangle for density?
mass
density | volume
17What is the equation triangle for moments?
moment
force | distance
18What are moments?
The turning effect of a force, measured to see what extent a force applied to an object causes it to rotate
19What does the principle of moments state?
sum of moments by multiple forces on single point = the moment caused by the resultant force (anti c-wise moment=c-wise moment)
20What directions can turning moments be?
Clockwise or anti-clockwise
21How do you find the net (total) moment?
sum clockwise moments and subtract anticlockwise moments
22What is the centre of gravity of an object?
The point on an object which we can model all the weight of the object to act through
23What has to happen for an object to be in equilibrium?
No resultant force
No resultant moment
24How to measure the density of a regular solid?
Using digital callipers with resolution of 0.01cm (for lengths up to 15cm)
Using a metre rule with resolution of 1.0mm (lengths over 15cm)
25How to measure density of irregular solid?
Solid is lowered into measuring cylinder of water by thread until fully submerged
Increase in volume reading = volume of the solid
26What method do you use to measure density of irregular solids if the solid is too large for normal method?
Lower solid into displacement can
Water overflow is captured by measuring cylinder
27What are disadvantages of using the other method to measure density of irregular solids?
The resolution of measuring cylinder is quite large
Volume of water overflowing is not exactly the same as volume of solid
28Explain density
The measure of how tightly matter is packed together (mass) inside of a given area (volume)
29How to find an unknown mass using principle of moments?
Metre ruler balanced on clamp stand
Put 200g on, measure how far it is from pivot after balancing
Calc mass of metre ruler using pom
Do same thing as 200g with unknown mass
Calc unknown mass using pom
Check if its right using a top pan balance