Jawaban:

Sejumlah N buah balok dengan massa yang sama berada di atas lantai yang licin dan disusun seperti pada gambar.space

Balok yang paling kanan ditarik dengan gaya F ke kanan. Besarnya tegangan tali antara balok 2 dan 3 adalah ….space

begin mathsize 14px style fraction numerator N minus 2 over denominator N end fraction F end style

begin mathsize 14px style fraction numerator N minus 3 over denominator N minus 1 end fraction F end style

begin mathsize 14px style fraction numerator N minus 1 over denominator N end fraction F end style

begin mathsize 14px style fraction numerator N minus 3 over denominator N end fraction F end style

begin mathsize 14px style fraction numerator N minus 2 over denominator N minus 1 end fraction F end style

Pembahasan:

Tinjau sistem benda untuk menghitung besar percepatannya.space

begin mathsize 14px style a equals fraction numerator straight capital sigma F over denominator straight capital sigma m end fraction a equals fraction numerator F over denominator N m end fraction horizontal ellipsis open parentheses 1 close parentheses end style

Tinjau balok 1 untuk menghitung besar tegangan tali 1, yaituspace

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell straight capital sigma F end cell equals cell m a end cell row cell F minus T subscript 12 end cell equals cell m a end cell row cell T subscript 12 end cell equals cell F minus m a end cell end table end style

begin mathsize 14px style T subscript 12 equals negative T subscript 21 end style adalah pasangan aksi reaksi, maka

begin mathsize 14px style T subscript 21 equals F minus m a horizontal ellipsis open parentheses 2 close parentheses end style

Subtitusi pers. 1 ke pers. 2

begin mathsize 14px style T subscript 21 equals F minus m a T subscript 21 equals F minus m open parentheses fraction numerator F over denominator N m end fraction close parentheses T subscript 21 equals F minus F over N T subscript 21 equals F open parentheses 1 minus 1 over N close parentheses horizontal ellipsis open parentheses 3 close parentheses end style

Tinjau balok 2 untuk menghitung besar tegangan tali pada benda 2.space

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell straight capital sigma F end cell equals cell m a end cell row cell T subscript 21 minus T subscript 23 end cell equals cell m a horizontal ellipsis open parentheses 4 close parentheses end cell end table end style

Subtitusi pers. 1 dan 2 ke pers. 4

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell T subscript 21 minus T subscript 23 end cell equals cell m a end cell row cell F open parentheses 1 minus 1 over N close parentheses minus T subscript 23 end cell equals cell m open parentheses fraction numerator F over denominator N m end fraction close parentheses end cell row cell T subscript 23 end cell equals cell F open parentheses 1 minus 1 over N close parentheses minus F over N end cell row cell T subscript 23 end cell equals cell F minus F over N minus F over N end cell row cell T subscript 23 end cell equals cell F minus fraction numerator 2 F over denominator N end fraction end cell row cell T subscript 23 end cell equals cell open parentheses fraction numerator N minus 2 over denominator N end fraction close parentheses F end cell end table end style