Vectors Flashcards
What is a vector quantity
A physical quantity that has both magnitude and direction
What are examples of vector quantities
Displacement, velocity, acceleration, force, weight
What is a scalar quantity
A physical quantity that has magnitude only
What are examples of scalar quantities
Time, mass, distance, speed, charge
What is a resultant vector
The single vector which has the same effect as the original vectors acting together
How do we indicate a vector quantity
With a straight line and an arrow point
How do we represent vectors on the Cartesian plane
Rx is a vector in the horizontal direction and Ry is a vector in the vertical direction
What are collinear vectors
Two or more vectors operating in one and the same dimension
What should we do when adding collinear vectors algebraically
- Vector equation
- State which direction in positive
- Sub in vectors
- Add vectors
- Substitute sign for direction
How do we find the magnitude and direction of perpendicular vectors
We use the tail to tail or head to tail method then use pythag and trigonometry to solve
How do we add vectors that are not collinear or perpendicular
- Find x and y components of each force
- Add collinear forces
- Once you have two perpendicular forces. Use head to tail or tail to tail method to solve
What is equilibrium
When the resultant of two or more forces exerted on a point are zero
What is the équilibrant
The single force which keeps the other forces in equilibrium. The équilibrant has the same magnitude as the resultant but operates in the opposite direction.
What is the triangle rule of three forces in equilibrium
When the forces exerted at a point are in equilibrium, their magnitude and direction can be represented sequentially by the sides of a triangle
What is the component of a vector
Two or more vectors which together have the same effect as the original vector. Components can be in any direction
What is a force
A pull or a thrust in a certain direction acting on an object.
What are forces classified into
Contact and Non-contact forces
What are contact forces
Forces exerted by objects on each other when they touch
What are non-contact forces
Forces which objects are exerting on each other without contact
What are examples of contact forces
Exerted forces (thrust or pull)
Tension
Normal force
Air friction
Resilience
What are examples of non-contact forces
Weight
Magnetic forces
Electrostatic forces
What is an applied force
A force exerted on an object by a person or another object
What is weight
The gravitational force the Earth exerts on any object on or near its surface.
What is normal force
The perpendicular force exerted by a surface on an object in contact with it
Define friction force
The force that opposes motion of an object
What it’s air friction
The resistance for Exerted on a moving object by the collision of air particles. It operates in the opposite direction as motion.
In what direction does friction act
Next to or Parallel to the surface and in the opposite direction of motion
What is the magnitude of the friction force dependant on
The nature of the two surfaces in contact
What are the two types of friction
Static friction and kinetic friction
What is static friction
The frictions force exerted by one surface on another when there is no motion
What friction needs to be overcome in order to move a static object
Static friction
What is maximum static friction
The static friction just before an object moves
What is kinetic friction
The frictional force a surface exerts on an object when the object is moving across the surface
What is the static coefficient
The relation Fs(max)/N of the two surfaces involved.
What is the coefficient of kinetic friction
The relation fk/N for the two surfaces involved
What is Newton’s first law
An object continues in a state of rest or uniform velocity unless it is acted upon by a net or resultant force
What is inertia
The property of an object that causes it to resist a change in its state of rest or uniform motion
What is Newton’s second law
When a net force Fnet is applied to an object of mass m, it’s accelerates in the direction of the net force. The acceleration a is directly proportional to the net force and inversely proportional to the mass
What is Newton’s third law
When an object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A
What is newtons law of universal gravitation
Every particle with mass in the universe attracts every other particle with a force which is directly proportional to their masses and inversely proportional to the square of the distances between their centres
What is a gravitational field
A region in space where a mass will experience a force
What Is gravitation force
The force acting per unit mass
Where is the gravitational field of an object the strongest
At its surface
How to draw gravitational lines
Acting towards the surface of the object encircle the object, do not touch. Further away more spread out. If shown two dimensionally field lines go straight down with equal spacing
What factors influence gravitational force
Mass of the objects and distance between their centres
If a graph is plotted between gravitational force and the product of the masses what would be produced
A straight line graph that passes through the origin
If a graph is plotted between gravitational force and the distance of the masses what would be produced
A hyperbola
If a graph is plotted between gravitational force and 1/distancewhat would be produced
A straight like graph passing through the origin
What is the formula for newtons universal law of gravity
F = Gm1m2
————
d^2
What is the formula for the gravitational force of an object using its mass and gravitational acceleration
Fg = mg
What is mass
The amount of matter an object consists of and it is the same throughout the universe
What is gravitational acceleration
The acceleration that a falling object experiences due to the gravitational attraction force of the Earth on the object in the absence of air friction
What is the formula for gravitational acceleration
g = Gm(earth)
—————
d(earth)^2
Does the mass of an object affect the gravitational acceleration of a planet
No, Galileo proved this at the tower of pizza
When is an object truly weightless as opposed to when people describe something as weightless
When it is somewhere in the universe where the gravitational field is zero and the force of gravity on the object is also zero. However when people describe something is weightless they are referring to the feeling when no contact forces are acting on an object other than gravity
What is terminal velocity
The maximum velocity that can act on an object
When a skydiver jumps from an airplane and Fnet = Fg what is the acceleration.
a = g = 9,8
When a skydiver jumps from an airplane and Fnet = Fg - Fair what is the acceleration
a < g = 9,8
When a skydiver jumps from an airplane and Fnet = Fg - Fair = 0 what is the acceleration
a = 0
