written 5.8 years ago by |
Effort = $p = \frac{S_2 – S_1}{2}$
Power $= p \times h$
Numerical:
$h = \frac{y}{x} (r_2 – r_1)$
$60 = \frac{100}{150} (r_2 – 80)$
$r_2 = 170 \ mm$
$N_1 = 300\ rpm$ $\rightarrow$ $r_1 = 80\ mm$
$N_2 = ?$ $\rightarrow$ $r_2 = 170\ mm$
$\rightarrow$ $S = \frac{S_2 – S_1}{h}$
$S = 25\ N/mm, h = 60\ mm$
Diagram
$w_1 = \frac{2 \pi \times 300}{60} = 31.41$ rad/sec
$Fc_1 = mr_1 \ w_1^2$
$= 4 \times 0.08 \times 31.41^2$
$= 315.708\ N$
$\sum M_o = 0 \curvearrowright$ +
$[ \frac{mg + S_1}{2} ] (Y_1) – FC_1 (X_1) = 0$
$\frac{S_1}{2} \times 0.1\ – \ 315.708 \times 0.15 = 0$
$S_1 = 947.134 \ N$
[2] $\sum M_o = 0 \curvearrowright$ +
$[ \frac{mg +S_2}{2}] (Y) – Fc_2 (X) = 0$
$\frac{2447.124}{2} \times 0.1\ – \ Fc_2 (0.15) = 0$
$Fc_2 = 815.708 N$
$s = \frac{S_2 – S_1}{h}$
$25 = \frac{S_2 – 947.124}{60}$
$S_2 = 2447.124 \ N$
$\rightarrow$ $Fc_2 = mr_2 w_2^2$
$815.708 = 4 \times 0.17 \times w_2^2$
$w_2 = 34.63 \ rad/sec$
$w_2 = \frac{2 \pi N_2}{60}$
$N_2 = 330.69\ r.p.m$
$\rightarrow$ Effort, $p = \frac{S_2 – S_1}{2}$
$P = 750\ N$
$\rightarrow Power = p \times h = 750 \times 0.06 = 45\ N.m$