Roboguru

Sebuah benda dikenai tiga buah gaya seperti gambar berikut.   Resultan ketiga vektor tersebut sebesar . . . . (  )

Pertanyaan

Sebuah benda dikenai tiga buah gaya seperti gambar berikut.

 

Resultan ketiga vektor tersebut sebesar . . . . ( begin mathsize 14px style sin space 37 degree equals 0 comma 6 end style ) 

  1. begin mathsize 14px style 20 space straight N end style 

  2. Error converting from MathML to accessible text. 

  3. Error converting from MathML to accessible text. 

  4. begin mathsize 14px style 20 square root of 3 space straight N end style 

  5. Error converting from MathML to accessible text. 

Pembahasan Soal:

Diketahui :
stack F subscript 1 with rightwards harpoon with barb upwards on top equals 40 space N stack F subscript 2 with rightwards harpoon with barb upwards on top equals negative 24 space N stack F subscript 3 with rightwards harpoon with barb upwards on top equals 20 space N sin space 37 degree equals 0 comma 6  

Ditanyakan :
R space ? 

Pembahasan :

Karena begin mathsize 14px style F with rightwards arrow on top subscript 1 end style dan begin mathsize 14px style F with rightwards arrow on top subscript 3 end style memiliki arah yang berlainan, maka dapat langsung dicari resultan dari dua gaya tersebut:

begin mathsize 14px style F with rightwards arrow on top subscript 13 equals F with rightwards arrow on top subscript 1 minus F with rightwards arrow on top subscript 3 F with rightwards arrow on top subscript 13 equals 40 minus 20 F with rightwards arrow on top subscript 13 equals 20 space straight N end style 

Selanjutnya uraikan gaya ke dalam sumbu x dan y:

Resultan space gaya space pada space sumbu minus straight x space colon F with rightwards arrow on top subscript 2 x end subscript equals 24 space straight N F with rightwards arrow on top subscript 13 x end subscript equals 20 space cos 53 degree F with rightwards arrow on top subscript 13 x end subscript equals 20 cross times 0 comma 6 F with rightwards arrow on top subscript 13 x end subscript equals 12 space straight N F with rightwards arrow on top subscript x equals F with rightwards arrow on top subscript 13 x end subscript minus F with rightwards arrow on top subscript 2 x end subscript F with rightwards arrow on top subscript x equals 12 minus 24 F with rightwards arrow on top subscript x equals 12 space straight N Resultan space gaya space pada space sumbu minus straight y space colon F with rightwards arrow on top subscript 2 y end subscript equals 0 space straight N F with rightwards arrow on top subscript 13 y end subscript equals 20 space s i n 53 degree F with rightwards arrow on top subscript 13 y end subscript equals 20 cross times 0.8 F with rightwards arrow on top subscript 13 y end subscript equals 16 space straight N F with rightwards arrow on top subscript y equals F with rightwards arrow on top subscript 13 y end subscript minus F with rightwards arrow on top subscript 2 y end subscript F with rightwards arrow on top subscript y equals 16 minus 0 F with rightwards arrow on top subscript y equals 16 space straight N Resultan space gaya space colon R equals square root of F with rightwards arrow on top subscript x squared plus F with rightwards arrow on top subscript y squared end root R equals square root of 12 squared plus 16 squared end root R equals square root of 144 plus 256 end root R equals 20 space straight N  

Jadi, jawaban yang tepat adalah A.

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 18 Juli 2021

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