Energy Calculation 4. What is the gravitational potential energy of an object that has a mass of 100kg it is 10m off of the ground? The gravity on Earth is measured at 9.8N/kg

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

Who was the first scientist to measure speed as distance over time?

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?