Were all gonna die in this physics placement test...
Newtons laws
1st - An object at rest will remain at rest, an object in motion will remain in straight line motion unless acted upon by an external force. 2nd - If a net force is acting upon the object, the object will accelerate in the direction of the force. The acceleration is proportional to the force and inversely proportional to the mass. F=ma 3rd - For every acting force there is an equal but opposite force, the law of action and reaction.
Acceleration due to gravity
9.8m/ss 32ft/ss. Directed vertically downward. Acceleration of a body moving under the force of gravity, g.
Normal force
A force on an object that is supported by a surface, the force is perpendicular to the supporting object.
Newtons Force
A push or a pull that changes the velocity of an object. Force is a vector of quantity. Newton is SI unit of force. 1N makes a 1kg object move 1m/ss. Pound version is 4.45N
Speed
A scalar quantity. Average speed = Vector displacement/time taken V=s/t
Friction force
A tangential force acting between two or more objects when physically touching. When the applied force exceeds the maximum static friction an object will begin to slide.
Acceleration
A vector quantity. Average Acceleration = change in velocity vector/time taken
Velocity
A vector quantity. Contains a direction and a speed. Vector Displacement/Time Taken
Displacement
A vector showing the initial location to final location
Dimensional Analysis
All mechanical quantities can be described by length, mass and time.
Universal law of gravitation
Anything that has mass has a gravitation force it emits, and is attracted to other gravitational forces.
How to display vectors
Draw them with arrows, start at the intended point and go the intended direction and at the end of the line there NEEDS to be an arrow
Conservation of energy
Energy cannot be created or destroyed, but only transformed from one kind to another.
Kinetic Energy
Energy possessed by an object because it is in motion KE=1/2 m*v^2
Work
Force over a period of time. Where a force acts on a body that undergoes a vector displacement. W = F*cos(@)*s s= vector displacement. SI unit is a newton-meter, called a Joule
Concurrent Forces
Forces whose lines of action all pass through a common point.
Weight
Gravitational force acting downward on an object.
Unit Vectors
Magnitude of one and are represented by a boldface symbol topped with a caret. Rx i^
Tensile force
Magnitude of the tensile force is the tension
Mass
Measure of the inertia of an object.
Perfectly Elastic collision
No loss of kinetic energy in the collision
Vector
Quantity that posses a magnitude and direction.Displacement, Velocity, Acceleration, and force
Angular speed
RPM, rotations per minute, degrees per minute, radian per minute
Instantaneous Velocity
The average velocity evaluated for a time interval that approaches zero.
Angular motion
The displacement in degrees, not an actual distance measurement
Torque (or moment)
The effectiveness of the force in producing rotation about the axis. Torque = r*F*sin(@). r is the radial distance from the axis to the point of application, the radius. Units are Nm (newton meters)
Gravitational Potential Energy (GPE
The energy possessed by an object because of the gravitational interaction.
Energy
The measure of the change in a system. Uses Joules too. An object capable of doing work possesses energy
Center of Gravity
The point where the entire eight of the object may be concentrated.
Impulse
The product of a force. Impulse = force*length of time the force acts. SI unit is N*s. Impulse causes a change in momentum. Impulse = Change in momentum. F*(change in time) = m*(final velocity-initial velocity)
Component vectors
The resultant of a vector in three dimensions. cos=Rx/R-> sin=Ry/R->
Newtons Inertia
The tendency of a body to remain at rest, and of a body in motion to continue moving with an unchanged velocity
Power
Time rate of doing work. Average power = work done by force/time taken to do this work = force*speed
Total momentum before impact=?
Total momentum after impact
Velocity Components (how to find velocity with angles)
Vx=Vcos(@) Vy=Vsin(@)
Centripetal acceleration
When a point is moving with a constant speed around a circle (the direction is always changing)
Coefficient of static friction
When one surface is on the verge of sliding across another (when the maximum static friction has been exceeded). = Maximum friction force/normal force
Coefficient of kinetic friction
When one surface is sliding across another at a specific speed = friction force/normal force
Center of mass
Where all the mass is concentrated. Used to describe how an object will react to certain forces.
Equilibrium
Where forces are acting upon an object but it is not accelerating. The result of all forces must be zero.
Linear momentum
mass of body*velocity of body p=mv
