Mechanics and Materials Flashcards
Conditions for an object to be in equilibrium
Net resultant force of 0
Principle of moments applies
What is a couple?
Equal and opposite forces acting on object to make it rotate
Principle of moments
Clockwise moments=Anticlockwise moments
Moment
Force x perpendicular distance from the line of action
Coefficient of friction
FMAX = μR
What is Newton’s first law?
An object stays at rest or constant velocity unless an resultant force acts upon it
What’s Newton’s second law
The force exerted by an object is determined by its own mass and acceleration
What’s Newton’s Third Law?
Every action has an opposite and equal reaction
Terminal Speed/Velocity
All objects (independent of mass) accelerate to the ground at the same rate, due to their weight. Objects with a larger mass experience a larger force so that the rate of acceleration stays the same
What is thinking distance and what is its relationship with speed?
the distance travelled between spotting a hazard and hitting the brakes. As the speed increases or doubles so does the thinking distance due to the equation s= vt
What is braking distance and how does it change with thinking distance?
the distance travelled between hitting the brakes and the car coming to a halt. Braking distance quadruples as thinking distance doubles as it is proportional to kinetic energy which has speed^2
Stopping distance
the total thinking and braking distance
Drag force
The force of fluid resistance on an object moving through the fluid
3 conditions that affect the drag force on an object
Surface area of object
Viscosity of the fluid
Speed of the object
Friction
force opposing the motion of an object’s surface that moves or tries to move across another surface
