You throw a 0.84-kg rock straight up from a height of 12 m with a speed of 25 m/s. Answer the following questions: 1- Calculate the speed of the rock when it is 30 m above the ground. 2- At what height is the speed of the box 10 m/s? 3- Calculate the maximum height the rock can reach

Juan created a chart to him study for a test. which headings best complete the chart? x: transparent objects y: opaque objects x: opaque objects y: transparent objects x: high frequency waves y: low frequency waves x: low frequency waves y: high frequency waves

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?

An atom that has gained or lost electrons is called an _