Physics

Local context: what changes in United States

Straight to the numbers — here is how Physics behaves under US rules, units and pricing conventions.

Key local facts

• Money & format: Amounts are US dollars written as $1,234.56, with a period as the decimal mark. Sales tax is added at checkout, so advertised prices are pre-tax.
• Tax structure: Federal income tax runs in brackets from 10% to 37%, on top of state income tax that ranges from 0% (TX, FL, WA) to over 13% (CA).
• Payroll: FICA takes 7.65% from the employee (6.2% Social Security + 1.45% Medicare) and the employer matches it; Social Security stops at the annual wage base.
• Units: Imperial by default: miles, pounds, °F, US gallons and feet/inches. A US gallon is 3.785 L, not the 4.546 L imperial gallon.
• Power & standards: Households run on 120 V / 60 Hz with NEMA Type A/B plugs, and wiring sizes follow AWG under the NEC, not mm².

Local examples

• Example — Texas: A homeowner in Austin runs Physics with local rates, then checks the output against a contractor quote before signing.
• Example — New York: A freelancer in NYC uses Physics to separate federal, state and city obligations before setting aside quarterly estimates.

Every figure above applies to United States specifically and is reviewed when the rules change.