A0.25-kg ball attached to a string is rotating in a horizontal circle of radius 0.5 m. if the ball revolves twice every second, what is the tension in the string?

19.74 N

Explanation:

mass of ball (m) = 0.25 kg

radius (r) = 0.5 m

time (t) = 2 revolutions per seconds = 1/2 = 0.5 second per revolution

find the tension in the string

tension (T) =

tension now becomes (T) =

tension (T) =

tension (T) =

tension (T) =   =   = 19.74 N

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

0.55x745.7j and a calculator