Topic 2A Flashcards
Average velocity
displacement/change in time
acceleration
change in velocity/ time
Newton’s second law of motion
It states that when a net force acts on an object, the change in the object’s state of motion will be inversely proportional to the mass (m) of the object and directly proportional to the net force acting on the object
Fnet =ma
Newton’s first law
law of inertia— a body at rest remains at rest, or, if in motion, remains in motion, at a constant velocity unless acted on by a net external force.
Fg = ?
Newton’s third law of motion
Forces always occur in pairs, and one body cannot exert a force on another without experiencing a force itself. Whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that it exerts. Mathematically, if a body A exerts a force F on body B, then B simultaneously exerts a force –F on A.;
“action-reaction” law— where the force exerted is the action and the force experienced as a consequence is the reaction.
Static friction
exists between two objects that are not in motion relative to each other Can take on many values, depending on the magnitude of an applied force
Kinetic friction
exists between two objects that are in motion relative to each other. Is a constant value It converts kinetic energy to thermal energy by generating heat
Center of mass
Torque equation
Torque = (radius)(force)sin(angle b/t F and the lever arm)
Work formula
Work = (Force)(displacement)cos(angle b/t the force vector F and the displacement vector d)
mechanical advantage formula
mechanical advantage = (length of incline) / (height of incline)
6 simple machines
Plane Wedge
- Double distance of wedge/ramp = half force needed Wheel & axle Lever
- Doubling length of lever arm = half force needed Pulley
- Vectors of tension going up help to lift force up
- Work required to lift mass hasn’t changed, just force Screw
Efficiency
the ratio of the machine’s work output to work input when nonconservative forces are taken into account.
work-energy theorem
the work done by all forces acting on a particle equals the change in the particle’s kinetic energy.
kinetic energy formula
KE = (1/2)mv^2
Potential energy formula
potential energy (J) = (mass)(gravitational acceleration)(height)
Spring force- potential energy
PE = (1/2) mx^2
Hooke’s law
F = -kx (k = spring constant)
power equation
power = work/time
Power using ohms law
power = current x voltage
frequency equation
frequency = 1/period
period = the duration of each cycle
angular frequency =
refers to the angular displacement per unit time and is calculated from the frequency with the equation:
angular frequency = 2π(frequency)
wavelength equation
wavelength = velocity / frequency
density equation
density = mass/volume
