A turnbuckle is needed to apply an 8kN force on a cable. If the efficiency of the turnbuckle is 40% and the force applied is 159.155N with a lever of 20cm in length.
a)Find Mechanical Advantage:
M.A.=Load/Effort
M.A.=8000/159.155
M.A.=50.265 (ans.)
b)Find the velocity ratio:
Efficiency=M.A./V.R.
V.R.=M.A./eff.
V.R.=50.265/0.4
V.R.=125.66 (ans.)
c)Find the mean pitch of thread:
V.R.=distance moved by effort/dist. moved by load
V.R.=2piL/2*pitch of thread
2*pitch of thread=2pi*200mm/125.66
Pitch of thread=10/2
Pitch of thread=5mm (ans.)
Is this correct?
yes
First, let's go through the calculations to verify if the answers are correct:
a) Mechanical Advantage (M.A.)
The formula for mechanical advantage is Load divided by Effort:
M.A. = Load / Effort
Given that the Load is 8kN (8000N) and the Effort is 159.155N, we can substitute these values into the formula:
M.A. = 8000 / 159.155
M.A. ≈ 50.265
Your calculated Mechanical Advantage is correct: M.A. = 50.265.
b) Velocity Ratio (V.R.)
The formula for velocity ratio is Mechanical Advantage divided by Efficiency:
V.R. = M.A. / Eff.
Given that the Mechanical Advantage is 50.265 and the Efficiency is 40% (or 0.4), we can substitute these values into the formula:
V.R. = 50.265 / 0.4
V.R. ≈ 125.6625
Your calculated Velocity Ratio is correct: V.R. ≈ 125.6625.
c) Mean Pitch of Thread
The formula for the velocity ratio is:
V.R. = Distance moved by Effort / Distance moved by Load
We are given the Lever length as 20cm (or 200mm) and the Velocity Ratio as 125.6625, so we can rearrange the formula to solve for the mean pitch of the thread:
2 * Pitch of thread = (2π * Lever length) / V.R.
Pitch of thread = (2π * Lever length) / (V.R. * 2)
Substituting the values:
Pitch of thread = (2π * 200) / (125.6625 * 2)
Pitch of thread ≈ 5.026548
Your calculated Mean Pitch of Thread is approximately 5.026548, which is rounded up to 5mm. So, your final answer is correct: Pitch of thread = 5mm.
Overall, your calculations and answers are correct. Well done!