tolong bantu mencari cara utk no 14

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Diket : 
panjang awal dawai, L = 80 cm = 0,8 m
panjang akhir dawai, L' = 83 cm = 0,83 m
pertambahan panjang dawai, ΔL = 0,03 m
diameter, d = 1 mm = 10⁻³ m
Modulus Young, E = 2,5 x 10¹¹ N/m²

Tanya :
Gaya, F = __?

Jawab :

E = (F/A) / (ΔL/L)
E = (F.L) / ( A.ΔL)
E = (F.L) / ( π/4.d².ΔL)

F = (E.π/4.d².ΔL) / L

F = (E.π.d².ΔL) / 4L

F = (2,5 x 10¹¹.π.(10⁻³)².0,03) / 4.(0,8)

F = 7,5.π x 10³ / 3,2

F = 2,34375.π x 10³

F = 7,359375 x 10³ N

Jawaban : E


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
)|(
FZA