Air is a mixture of what?
1. Elements
2. Atoms
3. Compounds
4. Molecules

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?