B1. A stone is dropped from the cliff. If the height of the cliff is 200cm.
(a) calculate
(1)
Potential energy after falling for 20 seconds

What is the magnification of a real image if the image is 10.0 cm from a mirror and the object is 50.0 cm from the mirror ? use the equation m=-di/do. a. -5.0 b. 5.0 c. 0.20 d. -0.20

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?

What is the kinetic energy of a baseball moving at a speed of 40 m/s if the baseball has mass of 0.15 kg?