R= 4H b. 4R =H
2H = R
d. None of these
A cannon ball has a range R on a horizontal plane, such that the corresponding possible maximum
heights reached are H, and H2. Then, the correct expression for R is

Afigure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 20.9 12000 200 3.33

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

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?