Doc Brown holds on to the end of the minute hand of the clock atop city hall. The tangential velocity of the minute hand is 0.419 m/s. If the minute hand is 4.0 meters long, what is the professor's centripetal acceleration?

The answer is frictional force

Amicroscope, because these cells are so small that you would not be able to see them, or what they attack without it.

It is 5 hope this you out 

According to the equation which describes the relation between the resistance, voltage and the current intensity [tex] v= i * r[\tex]where v is the voltage in volts, i is the current intensity in amperes, and r is the resistance in ohms.so for a giving v and r (substitute in the previous equation)120= 0.6 i (divide both sides by 0.6)i = 120/0.6i = 200 amperes