# Forces acting on a jet engine

1. Aug 30, 2010

### josh28

1. The problem statement, all variables and given/known data
A 1600kg jet engine is fastened to the fuselage of a passenger jet by just three bolts (this is the usual practice). Assume that each bolt supports one-third of the load.
(b) During flight, the plane encounters turbulence, which suddenly imparts an upward vertical acceleration of 2.8 m/s2 to the plane. Calculate the force on each bolt now.

2. Relevant equations
F = ma

3. The attempt at a solution
The force acting on the engine is the sum of all forces acting on the engine because of Newton's second law. So first I found the force of gravity on the engine
F=ma
F=1600(9.8)
F=15,680 N

then I found the force the turbulence had on the engine

F=1600(-2.8)
F= -4480 N

Then the sum of these forces is -4480 + 15,680 = 11,200
Then I divided this by 3, for the force on each bolt and got 3,733 N.

But when I typed this answer in it was not correct and I do not know what I am doing wrong.

2. Aug 30, 2010

### Andrew Mason

Is the total force on the engine that causes the upward acceleration greater than or less than the force of gravity on the engine?

How about just prior to the upward acceleration - the plane travelling at constant altitude. What is the upward force on the engine (provided by the bolts) equal to?

AM