Respuesta :
Answer:
13) f2 = 105 cycles/sec
14) F2 = 3.375 lbs
Explanation:
Part 13)
- The frequency (f) of a vibrating string varies inversely as its length (L):
f = k / L
Where, k = proportionality constant
- Set up proportionality constant to equations as follows:
k = f1*L1 = f2*L2
Where, f1 = 175 cycles/s , L1 = 3 ft
f2 = ? , L2 = 5 ft
- Using the relationship we determine f2:
f2 = f1*L1 / L2
f2 = 175*3/5
f2 = 105 cycles/sec
Part 14)
- The force (F) of the wind blowing on a vertical surface varies jointly as the area of the surface (A) and the square of the velocity ( v^2):
F = k*A*v^2
F / A*v^2 = k
Where, k = proportionality constant
- Set up proportionality constant to equations as follows:
F1 / A1*v1^2 = F2 / A2*v2^2
Where, F1 = 75 lbs , A1 = 500 ft^2 , v = 50 mph
F2 = ? , A2 = 10 ft^2 , v = 75 mph
- Using the relationship we determine F2:
F2 = F1 * ( A2*v2^2 / A1*v1^2 )
F2 = 75*( 10*75^2 / 500*50^2 )
F2 = 3.375 lbs
