When light with a frequency f1 = 547.5 thz illuminates a metal surface, the most energetic photoelectrons have 1.260 x 10^-19 j of kinetic energy. when light with a frequency f2 = 738.8 thz is used instead, the most energetic photo-electrons have 2.480 x 10^-19 j of kinetic energy

using these experimental results, determine the approximate value of planck's constant.

express your answer using four significant figures.