Uhhhh...you should have paid attention in class, just saying...
A heat engine is a device that uses heat to produce useful work.
Answer: a) the greater speed for the ball is getting with the large radius of the circle. b) 1.68* 10 ^3 m/s^2 c) 1.25*10^3 m/s^2
Explanation: In order to solve this problem firstly we have to consider that speed in a of the circular movement is directly the angular rotation multiply the radius of the circle so by this we found that the second radius get large speed.
Secondly to calculate the centripetal acceleration for the ball we have to considerer the relationship given by:
acceleration in a circular movement= ω^2*r
so
a1= (8.44 *2*π)^2*r1=1.68 *10^3 m/s^2
a2= (5.95*2*π)^2*r2=1.25*10^3 m/s^2
1)a 2)D 3)a. I think the answers are
The current is defined as the amount of charge Q that passes through a given point of a wire in a time

:

Since I=500 A and the time interval is

the charge is

One electron has a charge of

, therefore the number of electrons that pass a point in the wire during 4 minutes is

electrons