Afluence of thermal neutrons is 6.5 x 10" d c m 2in a layer of muscle-equivalent tissue 0.1 gkm4 thick. what is the absorbed dose at the middle of the layer?
assume that the above neutron fluence is approximately uniform throughout
a tissue sphere 5 cm in radius, due to thermalization of a field of intermediate- energy neutrons penetrating the sphere. what is the absorbed dose at the center resulting from thermal-neutron-capture y rays? how does it compare with the total absorbed dose that results (directly or indirectly) from the thermal neu- trons?

Ithink the answer is fusion 

Answer mechanical energy;

C. it comes from the core of the earth.

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.