 #1
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 6
Homework Statement:
 Velocity Ratio, mechanical advantage, Efficiency in screw jack
Relevant Equations:

$$VR = \frac{2\cdot\pi \cdot R}{P}$$
$$M.A = \frac{/text{Load Lifted}}{\text {Effort Applied}}$$
$$\text{Efficiency} = \frac {M.A}{V.R}$$
Hello,
I have completed the question below.
I am just unsure on whether i am correct or not.
I am unsure on Mechanical Advantage. As i have seen a few different equations.
Question:
Answer:
a)
Velocity Ratio = $$\frac{\text{Distance Moved By Effort}}{\text{Distance Moved By Load}}$$
$$VR = \frac{2\cdot\pi \cdot R}{P}$$
$$ R = 180mm$$
$$P = 12mm$$
$$VR = \frac{2 \cdot \pi \cdot180mm}{12mm}$$
$$VR = 94.2$$
b)
$$M.A = \frac{\text{Load Lifted}}{\text {Effort Applied}}$$
$$\text{200kg to Newtons} = 1961.33$$
$$M.A = \frac{ 1961.33}{80}$$
$$ = 24.51$$
c)
$$\text{Efficiency} = \frac {M.A}{V.R}$$
$$\frac{24.51}{94.2}$$
$$ = 0.26$$
Are these correct? If not where have i gone wrong?
Thank you.
I have completed the question below.
I am just unsure on whether i am correct or not.
I am unsure on Mechanical Advantage. As i have seen a few different equations.
Question:
Answer:
a)
Velocity Ratio = $$\frac{\text{Distance Moved By Effort}}{\text{Distance Moved By Load}}$$
$$VR = \frac{2\cdot\pi \cdot R}{P}$$
$$ R = 180mm$$
$$P = 12mm$$
$$VR = \frac{2 \cdot \pi \cdot180mm}{12mm}$$
$$VR = 94.2$$
b)
$$M.A = \frac{\text{Load Lifted}}{\text {Effort Applied}}$$
$$\text{200kg to Newtons} = 1961.33$$
$$M.A = \frac{ 1961.33}{80}$$
$$ = 24.51$$
c)
$$\text{Efficiency} = \frac {M.A}{V.R}$$
$$\frac{24.51}{94.2}$$
$$ = 0.26$$
Are these correct? If not where have i gone wrong?
Thank you.