Dynamic Universe Flashcards
What is a vector quantity
A quantity with both magnitude and direction
What is a scalar quantity
A quantity with only magnitude
Absolute uncertainty
An error that has the same units as the quantity
Percentage uncertainty
(Random uncertainty/mean ) x 100
Scale reading
How well an instrument scale can be read
Digital
+-1 in the least significant digit displayed
Analogue
+- half the least division of the scale
Random uncertainties
Max value - min value / number
Systematic uncertainty
An error which effects all measurements in a way
Calibration uncertainty
An issue with a scale reading too high/low
Impulse
Impulse is a force that when applied changes the momentum of an object, the size of this change in momentum is dependant upon the size of the force and the time which it acts on the object
What is the Law of conservation of momentum
Total momentum before and total momentum after a collision are equal providing there are not external forces
What is red shift
Redshift is the relative change in wavelength due to the Doppler shift for a receding galaxy
What is time dilation
Time passes slower as you travel faster
As v tends to c, t tends to 0
