Sue whirls a yo-yo above her head in a horizontal circle. The yo-yo has a mass of 0.20 kg and is attached to a string 0.80 m long. Ignore the effect of gravity. (a) If the tension in the string is 5.0 N what will be the resulting speed of the yo-yo? (b) Determine the resulting period of the yo-yo’s revolution.

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?

In science and physics what is the standard unit of measure for speed?

Ablock having mass m slides down an inclined plane. the force of friction between the block and the inclined plane is f, the block's weight is m g, and the normal force is n. (a) draw a free – body force diagram showing the forces acting on the block. (b) write down all relevant newton’s equations for a given situation.