Wednesday
September 3, 2014

Homework Help: Is my math correct(2)

Posted by Henri on Monday, April 20, 2009 at 2:30pm.

What load can be lifted by a screw jack given:
Toggle1 length:520mm
Force applied:230N
Toggle2 lenght:445mm
Force applied:300.557N
Mean pitch of thread:13mm
S.J. efficiency:35%

My answer:
Assuming T2 to be 520mm long, the equivalent force would be:
0.445mX300.557N=0.52m X F2
F2=133.748/0.52
F2=257.2N
Assuming T1 as lifting the entire load:
Velocity Ratio of SJ=Circ of leverage/pitch of thread
V.R.=2pi0.52/0.013
V.R.=251.3
then:
Efficiency=Mech. adantage/V.R.
M.A.=251.3X0.35
M.A.=87.955
The load lifted by the Jack is:
M.A.=Load/effort
Load lifted=M.A.*(F1+F2)
Load=87.955*(230+257.2)
Load=42851.8/9.81
Load=4372.62kg/1000
Load=4.373tonnes

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Applied Mech. (with my answer..lol) - What load can be lifted by a screw jack ...
Please check my math - A turnbuckle is needed to apply an 8kN force on a cable. ...
Physics - A turnbuckle is needed to apply an 8kN force on a cable. If the ...
Physics (is this right?) - A turnbuckle is needed to apply an 8kN force on a ...
Physics - A turnbuckle is needed to apply an 8kN force on a cable. If the ...
Please check my math - A turnbuckle is needed to apply an 8kN force on a cable. ...
Velocity Ratio - Does my work make sense? A turnbuckle is needed to apply an 8kN...
physic - A turnbuckle is needed to apply an 8kN force on a cable. If the ...
science - A force of 625 N is applied to a hydraulic jack piston that is 0.04 m ...
Calculus - The efficiency E of a screw is given by E=T(1-0.35T)/T+0.35 where T ...

Search
Members