What common household substances can turn blue litmus paper red?

Which of the following represents an upright image? a. -do b. +m c. -m d. +do

How is zig zagging a form of acceleration?

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.