The electric field strength of the very long charged wire the linear charge density of the wire and as well as the force on the proton from that wire. Therefore, when the charge density is doubled, the proton would experience the same force magnitude if the distance between it and the wire is .

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings. 

250✖️100 to get you answer

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.