term 2 test Flashcards
Momentum
The product of an object’s mass and its velocity.
Linear momentum
A vector quantity with the same direction as the velocity
of the object.
Newton’s second law of motion in terms of momentum
The net (or resultant) force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force.
Impulse
Is the product of the resultant/net force acting on an object and the time the net force acts on the object.
System
A system is a collection of two or more objects that interact with each other
Isolated system
A system on which the resultant/net External force is zero
The principle of conservation of linear momentum
The total linear momentum of an isolated system remains constant (is conserved)
Weight
Gravitational force the earth exerts on any object on or near its surface.
Projectile
An object which has been given an initial velocity and then it moves under the influence of the gravitational force only.
Free fall
Motion during which the only force acting on an object is the gravitational force.
Work- energy theorem
The net work done on an object is equal to the change in the object’s kinetic energy.
Conservative force
Force for which the work done in moving an object between two points independent of the path taken.
Non-Conservative force
Force for which the work done in moving an object between two points depends on the path taken.
Principle of conservation of mechanical energy
The total mechanical energy (sum of gravitational potential energy and kinetic energy) in an isolated system remains constant
power
The rate at which work is done
heat of reaction (ΔH)
The energy absorbed or released in a chemical
reaction.
Define exothermic reactions
As reactions that release energy.
Define endothermic reactions
As reactions that absorb energy.
Activation Energy
The minimum energy needed for a reaction to take place.
Activated Complex
The unstable transition state from reactants to products.
Reaction rate
The change in concentration of reactants or products per unit time.
catalyst
A substance that increases the rate of a chemical reaction without itself undergoing a permanent change.
Gravitational Potential Energy
The energy an object has because of its position in the gravitational field relative to some reference point.
Open and closed systems
An open system continuously interacts with its
environment, while a closed system is isolated from its surroundings
A reversible Reaction
A reaction is reversible when products can be converted
back to reactants.
Chemical Equilibrium
It is a dynamic equilibrium when the rate of the forward
reaction equals the rate of the reverse reaction.
Le Chatelier’s principle
When the equilibrium in a closed system is disturbed, the
system will re-instate a new equilibrium by favouring the reaction that will oppose the
disturbance.
Collision Theory
According to the collision theory, a reaction between two substances A and B can only take place if the molecules (Particles) of A collide with the molecules (Particles) of B
