Question

An object spins with an angular momentum of 8.9 kg⋅m2 /s. A torque on the object causes it to slow to a stop in 5.2 s. What was the angular impulse on the object? What was the average torque on it? Analyze and Sketch the Problem

List Knowns and Unknowns Knowns Unknowns Li = ____________________ Lf = ________________ _____________ = ? ∆t = _________________ _____________ = ? SOLVE FOR THE UNKNOWNS a. Determine the angular impulse from the change in angular momentum b. Apply the impulse-momentum theorem to determine the Torque EVALUATE THE ANSWER Is the unit of torque correct? ______________________________________________________________ Is the magnitude of the torque realistic? _____________________________________________________

Answer 1

Step-by-step explanation:

Li = 8.9 kg m² /s , Lf = 0

Time = Δt = 5.2 s

Angular impulse = change in angular momentum = Li - Lf

= 8.9 - 0 = 8.9 kg.m²/s .

Average torque = angular impulse / time

= 8.9 / 5.2 = 1.711 kg m² / s²

Li = 8.9 kg m² /s , Lf = 0

Δt = 5.2 s

unit of torque = force x distance = mass x acceleration x distance

= kg . m /s² x m

= kg m² / s²