Question

Two identical blocks are placed 5 m apart. Each has a mass of 5 kg, is electrically neutral, and is made entirely of copper. Note: One copper atom has a mass of 1.055

Answer 1

a) neutral cu atom has 29electrons

b) cu atom mass due to electron= (296.61000/63)10²³ (9.110^-31)=0.0027kg

percentage of copper mass due to the electron =0.027%

percentage copper mass due to proton is=48.60   ( could be estimated in the same way as above only replace electron mass with the mass of proton.(mp=1.610^-27kg).

yes electeon and proton has same amount of charge and the rest amount of mass is due to the neutrons.

C) The number of electrons in each block is = 1/63(296.031000)10²³=2.610²⁶ electron

Total Charge of these electrons=-(1.6710^-19)(2.610²⁶)=-41600000C

Total carge of proton will also be the same as it is on electron but it will only be opposite in sign.

The total charge on the blok will be equal to zero.

d)

Fg= Fe

Gm1m2/r2= kq²/r2

q=Gm1m2/k= 8.610^-11 C is the net charge on each block now.

number of electron left=(2.610²⁶)(8.610^-11) /41600000

                                        =13109.75

number of block removed=41600000-1309.75=41586890.24

percentage of removal=41586890/41600000100/100= 99.96%

e) n The anount of repulsive force each block will experience is

Fc=kq²/r2

Fc=(910⁹)(41600000) / 25

Fc=1.4910¹⁶ N

Fc=1,410¹⁴     weight of jetliner