Physical Quantities, Units And Measurements Flashcards
Physical quantity
A physical quantity is one that has magnitude and a unit
Scalar quantity
A scalar quantity has only magnitude
Vector quantity
Vector quantity has both magnitude and direction
Prevent parallax error
Place your eyes perpendicular to the scale
Prevent zero error
Don’t include any dead space when you measure
When do we use a vernier caliper
To measure rounded objects (internal/external diameters of a beaker)
Advantages of an electronic vernier caliper
It is accurate
It shows direct readings
Disadvantages of electric vernier caliper
It’s expensive
It’s fragile
It uses cells
When do we use a micrometer screw gauge
For very short lengths (thickness of a coin)
Purpose of the ratchet on micrometer screw gauge
The ratchet prevents excessive force and deformation of the object
Define mass
Mass is the amount of particles contained in an object
Define volume
Volume is the amount of space occupied by an object
Precautions when using displacement method
- use a string to avoid splashing
- avoid parallax error
- view at lower meniscus
Define density and give its formula
Density is the amount of mass per unit volume
Density= mass
Volume
Why will density decrease if if temperature increases?
Density will decrease when temperature increases because volume increases when heat increases and mass is constant so it will be divided by a higher number
