U4 - Work Flashcards
Work Equation
Work = F(d)cos𝛳
What is the cosine in the work equation’s purpose
the cosine is the angle between displacement and the force you are finding the work done on
True or false you should use the magnitude of displacement and force in the work equation
True
What does cosine determine in the Work Equation
if the work being done is positive or negative
What does positive and negative work constitute
Positive work is when you add energy to the system. Negative work is when energy leaves the system.
What are the equations for the 3 types of mechanical energy
KE = ½mv² PE_g = mgh Pe_e = ½kx²
What is H in Gravitational potential energy equation
H is the horizontal zero line that you decide to set.
What is K in the elastic potential energy equation
K is the spring constant of a spring
What is conservation of mechanical energy
The conservation of mechanical energy in a system when there is no work due to a force applied or friction
Note: You can use conservation of mechanical energy to solve problems for the variables in the Me_i = Me_f equation
note
What is the work-energy theorem
W_Net = 𝚫KE
What equation do you use to find work due to friction
W_friction = 𝚫ME
What is the unit of work
Joules, 𝐽; Meter x Newton
What is the x in the elastic potential energy equation
displacement from equilibrium
What steps do you take to use conservation of mechanical energy?
You first identify the initial and final points. Then the horizontal zero line. Finally what types of energy are present. Then substitute and solve for variable.
