Mechanics And Materials Flashcards
What is Breaking Stress?
The maximum stress that an object can withstand before failure occurs.
What does Brittle mean?
A brittle object will show very little strain before reaching its break stress.
What is Centre of Mass?
The single point through which all the mass of an object is said to act.
What is Conservation of Energy?
The total momentum of a system before an event, must be equal to the total momentum of the system after the event, assuming no external forces act.
What is a Couple?
Two equal and opposite parallel forces that act on an object through different lines of action. It has the effect of causing a rotation without translation.
What is Density?
The mass per unit volume of a material.
What is Efficiency?
The ratio of useful output to total input for a given system.
What is Elastic Behaviour?
If a material deformation with elastic behaviour, it will return to its original shape when the deforming forces are removed. The object will not be permanently deformed.
What is an Elastic Collision?
A collision in which the total kinetic energy of the system before the collision is equal to the total kinetic energy of the system after the collision.
What is Elastic Limit?
The force beyond which an object will no longer deform elastically, and instead deform plastically. Beyond the elastic limit, when the deforming forces are removed, the object will not return to its original shape.
What is Elastic Strain Energy?
The energy stored in an object when it is stretched. It is equal to the work done to stretch the object and can be determined by the area under a force-extension graph.
What is Equilibrium?
For an object to be in equilibrium, both the resultant force and the resultant moment acting on the object must be equal to zero.
What is Hooke’s Law?
The extension of an elastic object will be directly proportional to the force applied to it up to the objects limit if proportionality.
What is an Impulse?
The change of momentum of an object when a force acts on it. It is equal to the product of the force acting on the object and the length of time over which it acts.
What an Inelastic Collision?
A collision in which the total kinetic energy of the system before the collision is not equal to the kinetic energy of the system after the collision.
