What is an order-of-magnitude estimate?
An estimate of a quantity’s scale as the nearest power of ten, rather than its precise value.
AQA A-level Physics (7408) · 3.1.3
Revise AQA A-level Physics (7408) specification point 3.1.3, Estimation of physical quantities, with free active-recall flashcards. Flip through the set or review every question and answer below.
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What is an order-of-magnitude estimate?
An estimate of a quantity’s scale as the nearest power of ten, rather than its precise value.
By approximately what factor do quantities differ if their orders of magnitude differ by one?
A factor of ten.
How can a physical quantity be estimated to an order of magnitude from available information?
Judge a plausible approximate value and express it as a power of ten in appropriate units.
How can estimated values be used to estimate another physical quantity?
Combine them using a relevant physical relationship, then express the result to the nearest order of magnitude.
How are powers of ten combined when estimated values are multiplied or divided?
For multiplication, add the powers; for division, subtract them.
Why is an order-of-magnitude estimate approximate?
It depends on the estimates and assumptions used.