Port-wine birthmarks can be removed by expose to 585 nm laser light. pulses are strongly absorbed by oxyhemoglobin in the capillaries in the birthmark, destroying them. a typical laser pulse lasts for 1.5 ms, and contains an energy of 7.0 j a. find the frequency and energy of each laser photon. b. how many photons are in each pulse in the given duration (1.5 ms)? explain if the numeric scale makes sense to you.

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.