What is the maximum mass that can hang without sinking from a 10.0-cm-diameter Styrofoam sphere in water

Abug is 12 cm from the center of a turntable that is rotating with a frequency of 45 rev/min . what minimum coefficient friction is required so that the bug stays on the turntable?

What will a positive and a negative charge do if they are separated from each other?

Which atomic model was proposed as a result of j. j. thomson’s work?