# Torque Required To Lift

## Homework Statement

Question refers to the torque required to lift the nose wheel of an aeroplane

A retracting nose wheel assembly is raised by the application of Torque T applied to link BC through a shaft B. The wheel and Arm AO have a combined mass of 50KG with a centre of mass at G. Find the value of T necessary to lift the wheel when D is directly under B at which position angle θ is 30 degrees

## Homework Equations

I have attached the figure that came with this question

T= r x F x Sinθ where T = Torque, r = Length of the Arm, F = Magnitude of the force and θ = the angle between the two arms, but i am unsure if this is what i use to find Torque required to lift

## The Attempt at a Solution

I have set up my own free body diagram representing this question however the part i am struggling with is setting up the equations required and getting started.
parts i am having problems with are for the Moment Arm (D) part of the equation, is this length BC and how do i determine the Force part of the equation, I know the mass is 50kg and acceleration is Gravity = 9.8 ? any help that could point me in the right direction would be greatly appreciated

#### Attachments

• Fig 1.1.jpg
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## Answers and Replies

Here is my attempt so far

F = 50 x 9.8
= 490 N

T = 500mm x 490 x sin(30)
T = 122.500

I have no idea to tell if this is on ther right track or not

Astronuc
Staff Emeritus
Science Advisor
One has to determine the force applied by arm CD acting at D, which lifts G through moment arm AG.

The force at D applies an opposite force at C on moment arm BC.

The torque at B must balance FC acting at C of moment arm BC. When D is directly under B, BC and CD are the two legs of an isoceles triangle with base BD.

Ok so would the Force acting at C Be the Weight of the wheel plus gravity acting to pull CD down? in this case 490 N? therefore the torque must be able to balance 490 N of opposite Force? I am still unsure how to determine the force required by Arm CD acting at D to lift G, and once i determine this Force how to translate it to Torque.