Mechanics Flashcards
What is Newton’s first law of motion?
A body will remain at rest or continue to move with a uniform velocity unless acted upon by a force
What is the metric system unit of force?
Newtons
What is the imperial system for force?
Pounds
What is the equation of force?
Force= mass x acceleration
What is a moment?
A turning effect produced by a force
What is another way to describe mechanical advantage?
A moment
What is the equation for a moment?
Moment= force x perpendicular distance
What is the definition of a fulcrum?
The point at which you pivot against/around
What is a couple?
A pair of forces that are equal in magnitude and different in direction i.e when a aircraft rolls the forces on both ends of wings one is up and one is down
What is a resultant force?
The effect that results from two or more vectors acting on an object i.e two people pushing a box at 500N and 330N is a resultant of 880N
When would you use the triangle method (Pythagoras) to work out a resultant force?
When you have two forces acting with a 90° angle
What theorem does the triangle method use?
Pythagoras theorem
What is a scalar?
Are quantities that have magnitude but no direction i.e length, distance, speed
What is a vector?
They have a magnitude as well as direction in a straight line i.e velocity, acceleration, force and momentum
What is the abbreviation CG stand for?
Centre of gravity
What is the force of gravitational pull?
9.8 per m/s^2
When choosing a datum for the aircraft what is the only fixed rule to follow?
The datum must be positioned in a location that will not change during the life of the aircraft
How would you find the CG of an aircraft?
You would calculate the moments affecting all landing gear and add them together then simplify to get a distance
What happens to an aircraft before it leaves the production line?
It goes under structural testing
What is the definition of stress?
A quantity that describes the magnitude of forces that cause deformation
What is deformation also known as?
Strain
Stress is always accompanied by?
Strain
What is the unit for stress in the metric system?
Pascal or N/m^2
What is the unit for stress in the imperial system?
Pounds per square inch (Psi)