6 Write down an expression for the velocity ratio of a pair of gear wheels.
What is the number of teeth in the driving wheel if the driven wheel has
60 teeth and the velocity ratio of the gear is 0.4? Why is this gear not
powerful to move a heavy car from rest?
No of teeth in the driven wheel
Hint: V. R.=
No of teeth in the driving wheel​

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present