PAGs paper 3 Flashcards
how can we measure mass
use a digital balance
Find the mass of the container, then the total mass and take them away
how can we measure volume in a liquid
use a measuring cylinder
how can we measure volume of a regular solid
use the measurements
how can we measure volume of an irregular solid
pour a known amount of water into a eureka can until it is dripping and allow any excess water to drip out till it stops
Put in the solid and then allow water to be collected in a measuring cylinder or beaker
Take this away from the original known volume of water
How to improve accuracy in measure volume
repeat
use vernier calipers (better rulers)
safety in measuring volume
keep the water away from the mass balance
mop up water if you drop it
method for the Hooke’s Law
- attach a spring to a clamp and let the spring hand freely over the bench
- Measure the length of the spring with no weights
- Slowly add masses to it
- Measure the length of the spring
- Take this way from the original length to find the extension
- repeat and record results
safety for hooke’s law
- wear ere protection
- make sure the clamp is securely fixed
- don’t make the masses bounce
- be careful that masses don’t fall onto feet
Equipment for measuring acceleration
trolley piece of card ramp ruler blocks to raise the ramp light gates and a data logger clamp and clamp stand
method for measuring acceleration
- raise the ramp using block and set up light gates on the lower end, connected to a data logger. Attach a card on the car
- Measure the distance of the ramp
- Let the trolley roll down the ramp from the top .
- when the card interrupts the beam, there will be a time
- use this data to find speed
- vary and blocks and find results
safety for measuring acceleration
runway may be heavy so may need 2 people to carry it
make sure the trolley doesn’t roll off the bench
parallel circuit
pd stays the same
current adds up
if u add another lamp the total current decrease and the net resistance decreases
series circuit
current is the same
pd across each component adds up to the pd near the battery
if you add another lamp the current decreases and the net resistance increases
safety cautions when working with circuits
filament bulbs may get hot so dont touch them
avoid short circuits
keep water away
filament lamp circuit components
as pd increases, current increases at a decreasing rate
The electrons in the wire collide with ions, that vibrate more as the wire gets hotter, meaning more collisions
Resistor circuit components
Resistance stays constant
pd increases as current does
linear circuit element
Diode circuit components
Only allows current in the positive direction
Resistance is decreasing as they are inversely proportional
Equipment for measuring SHC
1kg metal block with 2 holes low voltage heater in the block Low voltage power supply thermometer in block ammeter thermal insulation around block
Method for measuring SHC
- place the thermometer in the aluminium block and measure the starting temperature
- turn on the joulemeter and measure the starting energy
- switch on the power pack for 5 or so minutes
- measure the joulemeter reading and the temperature (measure its highest temperature as it might still keep climbing)
improving accuracy with SHC
Repeat
Insulate the block to reduce heat dissipation
Put oil in the hole to make it conduct electricity
Think about the height of the heater coming out of the block
Safety with SHC
Don’t touch the heater after its been turned off
NOT WITH WET HANDS
Switch off the heater if it’s burning
