People used to believe that if a penny was dropped ff Tom the Empire State Building, how fast would it be moving just before impact on ground? From release of your hand it takes 45 seconds falling at 9.8 m/s^2 due to gravity l.

99

Explanation:

600 mph

Explanation:

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 .

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this