Answer:
The answer is "[tex]\bold{11.428 \ in \ \ and \ \ 9.729 \ in}[/tex]".
Explanation:
The second question solution can be defined as follows:
[tex]N_A= 1000 \ rpm\\\\N_B=1575 \ rpm\\\\N_C=1850 \ rpm\\\\D_A= 18 \ in \\\\[/tex]
In point 1:
Calculating the value of the linear velocity is the same:
[tex]\to V_A=V_B\\\\\to \pi D_A N_A=\pi D_BN_B\\\\\to D_B= \frac{D_A \times N_A}{N_B}[/tex]
[tex]=\frac{18 \times 1000}{1575}\\\\=11.428 \ in \ \ \text{Diameter of pulley B}[/tex]
In point 2:
[tex]\to V_A=V_C\\\\\to \pi D_A N_A=\pi D_C N_C\\\\\to D_C=\frac{D_A \times N_A}{N_C}\\\\[/tex]
[tex]=\frac{1000 \times 18}{1850}\\\\=9.729 \ in \ \ \text{Diameter of pulley B}[/tex]