Physical Quantities and Measuring Techniques Flashcards
measuring cylinder for volume
they are normally used to find the volume of irregular shaped objects, where you use the displaced amount of water, to determine to volume of the object
ruler for length
to help you find the length of objects
how to measure time intervals
subtract the final value by the initial value
how to calculate the period of a pendulum
1 oscillation is the back and forth of a pendulum and the period is the time that the pendulum takes for 1 oscillation and so the pendulum will go to fast, that is why, try to measure the time it takes for the pendulum to oscillate 20 times and divide that time by 20
how to measure the thickness of something
if you want to measure a page, then you look at the thickness of the book, see how many pages it has and divide the thickness by the pages
stopwatches for time
to measure multiple periods like 20 periods
vector quantities
have magnitude and direction (acceleration, velocity, weight, force, gravitational field strength)
scalar quantities
only have magnitude/size
(mass, distance, speed, temperature, energy or time)
energy stores
- KINETIC ENERGY
- GRAVITATIONAL POTENTIAL
- CHEMICAL
- ELASTIC (STRAIN)
- ELECTRICAL
- HEAT
- LIGHT
- SOUND
- NUCLEAR
- INTERNAL
equation for kinetic energy
1/2 x m x v squared
equation for gravitational potential energy
mass x gravity x height
equation for change in gravitational potential energy
mass x gravity x change in height
energy is transferred between different stores, like when it transfers because of mechanical work done
when a force moves an object
like when we put books back in shelves
(chemical energy in muscles transferes to GPE in the shelf.)
electrical work done
electric currents (charges flow in a circuit,)
like when we use battery to power toys
(chemical energy in the battery is transferred to kinetic energy in the toy
heating
when energy moves from thermal store of warm object to cool object
like when hand warmers warm up your hand (thermal energy in the hand warmer, is transferred by conduction to thermal energy in your hands)
radiation
when energy is transferred as waves, such as heat, sound or light
like radiation form a toaster
(thermal energy of the grill is transferred to thermal energy in the food)
energy transfer when ball drops
total energy before = total energy after
(when a ball drops and falls to the ground, when it is at the top, the kinetic energy is at zero but the GPE is at its maximum, and just before it hits the ground, the GPE is at zero, but the KE is at its maximum
energy cant be..
created, it cant be destroyed, it can only be transferred
the sun
nuclear –> light and heat
a phone
chemical –> light, sound and heat
catapult
elastic –> GPE and kinetic
burning match
chemical + heat + light
