Q1=-q2=q3=2.10^-8 đặt tại A, B,C .tìm lực điện tổng hợp tác dụng lên q4=2.10^-8 đặt tại D sao cho ANCD là hình a, vuông vs a= 2cm
b, chữ nhật vs a=4cm, b= 2cm

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Order the sequence of ideas that lead to marie curies discovery of radioactive elements number the events in chronological order starting with the oldest

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information