Vẽ sơ đồ kết cấu và thuyết minh nguyên lý làm việc của máy phát điện 1 chiều ?

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great.d) about 10 times as great.

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?