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► An aeroplane has its centre of gravity located 7 metres from the datum line and it has a mass of 49000N. The moment about the datum is:
A) 343 000 Nm
B) 1,43 Nm
C) 7000 Nm
D) 34 300 Nm
Moment = arm x mass
Moment = 7 x 49 000
Moment = 343 000 Nm
► The position of the centre of gravity can always be determined by:
Answer: Dividing the total moment by the total mass
Moment = arm x mass
Arm = moment / mass
► Given: Block fuel: 100 gal
Trip fuel: 55 gal
Fuel density: 6 lbs/gal
Determine the Block Fuel moment:
A) 9.360
B) 56.160
C) 30.888
D) 430.546
Block fuel = 100gal (x6) = 600lbs
Arm for fuel (taken from the provided table) = 93.6
Moment = 93.6 x 600
Moment = 56 160
► (Refer to figure 031_8-5) For the following see-saw to be in balance:
A) Fb = A x Fa/B
B) Fb = A + Fa/B
C) Fb = A x B/Fa
D) Fb = B x Fa/A
For both sides to be in balance, the formula must be:
Force at A (Fa) x Arm at A (A) = Force at B (Fb) x Arm at B (B)
Fa x A = Fb x B
Now just reposition the formula for the value they ask (Fb):
Fb = (Fa x A) / B
A) 343 000 Nm
B) 1,43 Nm
C) 7000 Nm
D) 34 300 Nm
Moment = arm x mass
Moment = 7 x 49 000
Moment = 343 000 Nm
► The position of the centre of gravity can always be determined by:
Answer: Dividing the total moment by the total mass
Moment = arm x mass
Arm = moment / mass
► Given: Block fuel: 100 gal
Trip fuel: 55 gal
Fuel density: 6 lbs/gal
Determine the Block Fuel moment:
A) 9.360
B) 56.160
C) 30.888
D) 430.546
Block fuel = 100gal (x6) = 600lbs
Arm for fuel (taken from the provided table) = 93.6
Moment = 93.6 x 600
Moment = 56 160
► (Refer to figure 031_8-5) For the following see-saw to be in balance:
A) Fb = A x Fa/B
B) Fb = A + Fa/B
C) Fb = A x B/Fa
D) Fb = B x Fa/A
For both sides to be in balance, the formula must be:
Force at A (Fa) x Arm at A (A) = Force at B (Fb) x Arm at B (B)
Fa x A = Fb x B
Now just reposition the formula for the value they ask (Fb):
Fb = (Fa x A) / B
