which of the following is a non-contact force? Magnetic force, friction force, force applied by a boat man on the oars, or Force applied by a table on a book placed on it.

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

What causes most sediment to wash or fall into a river