Cho mạch điện như hình vẽ: Biết: R1 = 15, R2 = R3 = R4 = 20; RA = 0; ampe kế chỉ 2A.
Tính cường độ dòng điện qua các điện trở R1, R2, R3, R4.

Which statement best describes who the period and frequency of electromagnetic was change between gamma rays and microwaves? a) the period and frequency stay the same. b) the period increases and the frequency decreases. c) the period decreases and the frequency increases. d) the period increases and the frequency increases.

Aproton is projected toward a fixed nucleus of charge +ze with velocity vo. initially the two particles are very far apart. when the proton is a distance r from the nucleus its velocity has decreased to 1/2vo. how far from the nucleus will the proton be when its velocity has dropped to 1/4vo?

Iwill give brainliest if you answer right : )