Work and Energy Flashcards
translational equilibrium
An object that is not moving or an object that is moving in a straight line at a constant velocity
mechanical advantage
the ratio of the force produced by a machine to the force applied to it
used in pulley problems
efficiency
comparison of the energy output to the energy input in a given system
Wout/Win = (load x load distance)/(effort x effort distance)
Work-Energy Theorem
the total work done on any object is equal to the change in kinetic energy of that object
W = ΔK = Kf-Ki
Kinetic Energy
KE = 1/2mv^2
Potential Energy
energy stored within the system
PE = mgh
Gravitational potential energy
related to the mass of an object and its height above a zero-point
Elastic Potential energy
1/2Kx^2
K = spring constant (measure of stiffness)
Electrical potential energy
exists between charged particles
chemical potential energy
energy stored in the bonds of compounds
conservative foces
path independent, do not dissipate the mechanical energy of a system
ex: gravity, electrostatic forces
Nonconservative forces
path dependent and cause dissipation of mechanical energy from a system
ex: friction, air resistance, and viscous drag
Work
process by which energy is transferred from one system to another
Fdcosθ
PΔV
W = ΔK
Power
rate at which work is done or energy is transferred
P = W/t P = ΔE/t
how to increase pressure
increase force, increase temperature, increase number of moles (to increase collisions), decrease area
work function
the amount of energy that must be absorbed just to eject the photoelectron from the detector
therefore the equation is KE = hf - WF
how will the normal force be affected by increasing the tilt of a ramp?
the normal force will decrease because the increase in tilt will have the object pretty much free falling which only requires mass and rarely actually touches the ramp.
So Increase angle, Decrease normal force
