Modeling Elevator Dynamics | Dataford Interview Questions

Describe how you would derive the equations of motion for an elevator system with a pulley, including how you would use a free-body diagram.

Implement derive_elevator_equations(params) for an ideal rope connecting an elevator car and counterweight. Use an upward-positive car coordinate and return the effective mass, driving force, acceleration, and both rope tensions.

Constraints

params contains positive car_mass, counterweight_mass, pulley_inertia, pulley_radius, and gravity values
pulley_radius > 0
The rope is massless, taut, and inextensible
The pulley rotates without slipping
The elevator and counterweight move along one vertical axis
No friction or external motor torque is included

Function Signature

def derive_elevator_equations(params):

Your question is Modeling Elevator Dynamics. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Describe how you would derive the equations of motion for an elevator system with a pulley, including how you would use a free-body diagram.

Constraints

params contains positive car_mass, counterweight_mass, pulley_inertia, pulley_radius, and gravity values
pulley_radius > 0
The rope is massless, taut, and inextensible
The pulley rotates without slipping
The elevator and counterweight move along one vertical axis
No friction or external motor torque is included

Function Signature

def derive_elevator_equations(params):

Your question is Modeling Elevator Dynamics. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.