1) For an x-ray tube operating at 40 kV: a) Find Aswi b) Can this radiation be used to excite K and L lines of platinum (Pt). c) At this voltage, gold (Au) will produce (more, less, equal) amount of Bremsstrahlung radiation than nickel (Ni). d) If you put your hand in front of a Cu target x-ray tube operating at this voltage. Calculate the penetration depth (t) in um at which the Cu Ka x-rays will be attenuated to 1% of its original intensity, assuming your tissue has density of 1g/cm, and contains 90% HO, and 10% carbon by weight.