# Electric Field Equals Zero?

Can someone explain in detail the following formula? (Gradient)*E=0 (without source or current)

Can someone explain in detail the following formula? (Gradient)*E=0 (without source or current)

Dear Professor Cram: A waterskier is being pulled at a constant velocity of 15.8m/s. The drag force on the boat is 280N. What is the foce applied to the boat by the propellor? I don't even know where to start Continue reading

Dear Professor Cram On mars, the acceleration due to gravity is 3.71m/s2. What would a rock's velocity be 0.5 sec. after you dropped it on mars? What is the formula for this problem

Dear Professor Cram: An executive flew his corporate jet to a meeting in a city 1500 kilometers away. After traveling the same amount of time on return flight, the pilot mentioned that they still had 300 km to go. The Continue reading

Dear Professor Cram: I have a question about series circuits. There are 3 resistors, R1 is 10kohms/.5W and R2 is 3.3kohms/.250W and the third is unknown. If the circuit draws a current of 1.5mA from a 27V source, how do Continue reading

Dear Professor Cram: I'm not really sure how to tackle a problem like this… An inclined plane rests at a 37 degree angle with a box weighing 50N on it as a vector down. I'm supposed to find components of Continue reading

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