Which of the following is considered a physical change?

A:burning paper

B:rusting of metal

C:evaporating water

A solution of an acid in water has apH of 4, which is slightly acidic. Is this a solution of a weak acid?

Use the drop-down menus to explain how noise cancellation works. Waves with similar are created to interfere with unwanted sound waves. The wave overlap with the troughs of the other wave, causing the two waves to cancel out each other. of one

How do we calculate the "range" of the measurements? a) subtract the smallest value from the largest value b) subtract the largest value from the smallest value c) add up all the measurements d) add up all the measurements and divide by the number

Scientist A believes she has discovered a new procedure that is better than a procedure currently in use by physicians. She tests her procedure on several occasions and achieves excellent results.

Filtration, decantation, and evaporation are examples of

Bus A and Bus B leave school on a field trip when a stopwatch reads zero. Bus A travels at a constant 50 km/h, and Bus B travels at a constant 75 km/h. How far are the two buses from school when the stopwatch reads 1.5 h?. a ... Bus A is 76.

When observed from Earth, the wavelengths of light emitted by a star are shifted toward the red end of the electromagnetic spectrum. Why does this redshift occur?

Object A has a length of 3 cm, a width of 10 cm, and a height of 2 cm. Object B is dropped into a graduated cylinder. It displaces 60 mL of water. The volume of object A is:

Is the following sentence true or false? Some information about an object or process may be missing from a model.

If V is a velocity, l a length, and v a fluid property having dimensions of L2T-1, which of the following combinations are qualitatively dimensionless (show work for a through d) : (a) V l v (b) Vl/v (c) V2v (d) V / (l v)