Theo mẫu nguyên tử Bo trong nguyên tử Hidro chuyển động của electron quanh hạt nhânlaf chuyển động tròn đều . Biết bán kính Bo ro = 5,3.10^-11 . Tốc độ của electron trên quỹ đạo dừng Bo thứ 2 bằng

Write the function getkthdigit(n, k) that takes a possibly-negative int n and a non-negative int k, and returns the kth digit of n, starting from 0, counting from the right

Aball horizontally thrown from a cliff at 8m/s

Aswimming pool whose volume is 10 comma 000 gal contains water that is 0.01% chlorine. starting at tequals0, city water containing 0.003% chlorine is pumped into the pool at a rate of 5 gal/min. the pool water flows out at the same rate. what is the percentage of chlorine in the pool after 1 hour? when will the pool water be 0.006% chlorine?