Abeam of protons is moving toward a target in a particle accelerator. this beam constitutes a current whose value is 0.50 μa. (a) how many protons strike the target in 15 s? (b) each proton has a kinetic energy of 4.9 x 10-12 j. suppose the target is a 15 gram block of aluminum, and all the kinetic energy of the protons goes into heating it up. what is the change in temperature of the block that results from 15 s bombardment of protons?

(a) The current is defined as the amount of charge that strikes the target per unit time:

where Q is the total charge and t the time.
We know the current, , and the time, , so we can calculate the amount of charge that strikes the target during this time interval:


We know that each proton has a charge of , so if we divide the total charge Q by the charge of one proton q, we find the number of protons that strike the target:


(b) The total energy given by the beam of protons to the block of aluminium is equal to the kinetic energy of one proton times the number of protons:


This energy is given as heat to the block of aluminium, and the increase in temperature of the block is related to this energy by

where m=15 g=0.015 kg is the mass of the block,  is the specific heat capacity of aluminium, and  is the increase in temperature that we want to find.

If we rearrange the equation, we find :

Hahahahaha nice. my guess would be age or they moved the grocery store. ; ) and remind him next time you are late getting home that it takes a long time to go 12miles, hahahave a good one!