# Is my forces sketch correct?

Gold Member

## Homework Statement

During an engine experiment of a plane, the plane stands horizontally, when one wheel is located on a special weighting apparatus. When the engine is active, the apparatus shows a pressure force of 8.5 [kN]; and when the engine is inactive, it shows pressure force of 4.5 [kN]. The increasing of the force due to the action of the engine is caused by the ation of the reactive momentum, that wants to turns the entire plane at the opposite drection to the direction of the propllelor.

(The question I'm struggling is this:)

Draw a sketch of the forces acting on the wheeks when the engine is off and when the engine is on.

(I solved the 1st question to thism finding the the reactive momentum is 12 if L is 3 [m])

http://img710.imageshack.us/img710/9413/planeq.jpg [Broken]

## The Attempt at a Solution

Attached... is this right?

#### Attachments

• planesketch.jpg
34 KB · Views: 333
Last edited by a moderator:

PhanthomJay
Homework Helper
Gold Member
The first sketch is good. The second is not. HINT: The weight of the plane does not change when the engine is turned on.

Gold Member
Ah...must be 8.5 to 0.5 right?

PhanthomJay
Homework Helper
Gold Member
Ah...must be 8.5 to 0.5 right?
Do you mean 8.5 kN up at the right support in the diagram, and 0.5 kN up at the left support?

Gold Member
Exactly, PhantomJ :)

PhanthomJay