Question

Find the energy stored in a 60 cm length of laser beam operating at 4 megawatt

Answer 1

2×(10-9)sis U=(4m W) xx (2 xx (10^-9)s)= (4 xx (10^-3)J(s^-1)) xx (2 xx (10^-9) s). = 8 xx (10^-12) J. ` The is the energy contained in 60 cm length.