a group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 12 rotations in 20.7 seconds when twirled.

What is the length x of the side of the triangle below? (hint: use the cosine function)

An object has a weight of 500 on earth what is the mass of this object

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton