user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: under what measurement system is poundal an angular velocity unit? 
Knowledge Triplets: Not believing in force is the same as not believing in gravitation., media_common.quotation.subjects, Force
Long ton, measurement_unit.mass_unit.measurement_system, Imperial unit system
Nautical mile, measurement_unit.distance_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.length_units, Mile
poundal.noun.01, base.wordnet.synset.lexname, noun.quantity
Force, measurement_unit.dimension.units, Poundal
Imperial unit system, measurement_unit.measurement_system.area_units, Square foot
Ounce, measurement_unit.mass_unit.measurement_system, Imperial unit system
Long quarter, measurement_unit.mass_unit.measurement_system, Imperial unit system
Peck (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.area_units, Acre
poundal.noun.01, base.wordnet.synset.equivalent_topic, Poundal
Imperial unit system, measurement_unit.measurement_system.length_units, Foot
Thousandth of an inch, measurement_unit.distance_unit.measurement_system, Imperial unit system
Cubic foot, measurement_unit.volume_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.length_units, Thousandth of an inch
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_lenght, Inch
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_lenght, Mile
Force, media_common.quotation_subject.quotations_about_this_subject, Force without forecast is to little avail.
Grain, measurement_unit.mass_unit.measurement_system, Imperial unit system
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_lenght, Foot
Imperial unit system, measurement_unit.measurement_system.volume_units, Gill (Imperial)
Force gauge, measurement_unit.measuring_instrument.dimension_measured, Force
Force is that which rules the actions without regulating the will., media_common.quotation.subjects, Force
Force, base.ontologies.ontology_instance.equivalent_instances, m.07nf14g
Imperial unit system, measurement_unit.measurement_system.weight_units, Ounce
League, measurement_unit.distance_unit.measurement_system, Imperial unit system
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_mass, Long ton
Imperial unit system, measurement_unit.measurement_system.volume_units, Cubic foot
Force, measurement_unit.dimension.units, Dyne
Imperial unit system, measurement_unit.measurement_system.volume_units, Quart (Imperial)
A man convinced against his will; is of the same opinion still., media_common.quotation.subjects, Force
Force, media_common.quotation_subject.quotations_about_this_subject, Be careful: they have arms, and no alternatives.
Poundal, measurement_unit.unit_of_force.measurement_system, Imperial unit system
Force, measurement_unit.dimension.units, Pound
Whatever needs to be maintained through force is doomed., media_common.quotation.subjects, Force
Foot, measurement_unit.distance_unit.measurement_system, Imperial unit system
Be careful: they have arms, and no alternatives., media_common.quotation.subjects, Force
Inch, measurement_unit.distance_unit.measurement_system, Imperial unit system
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_mass, Stone
Force, base.skosbase.vocabulary_equivalent_topic.narrower_concept, Work (Mechanics)
Hundredweight, measurement_unit.mass_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.volume_units, Fluid ounce (imperial)
Pound, measurement_unit.mass_unit.measurement_system, Imperial unit system
Force, user.avh.default_domain.ellerdale_topic.ellerdale_id, 009a-4298
Force, base.schemastaging.context_name.pronunciation, g.125_ryb22
Square mile, measurement_unit.area_unit.measurement_system, Imperial unit system
Cup (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Civilization is nothing more than the effort to reduce the use of force to the last resort., media_common.quotation.subjects, Force
Force, media_common.quotation_source.quotationsbook_id, force
Imperial unit system, measurement_unit.measurement_system.volume_units, Peck (Imperial)
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_volume, Fluid ounce (imperial)
Force, media_common.quotation_subject.quotations_about_this_subject, Force works on servile natures, not the free.
m.0qq7rnm, dataworld.gardening_hint.last_referenced_by, Force
poundal.noun.01, base.wordnet.synset.hypernym, force unit.noun.01
Imperial unit system, measurement_unit.measurement_system.volume_units, Pint (Imperial)
Link, measurement_unit.distance_unit.measurement_system, Imperial unit system
Force works on servile natures, not the free., media_common.quotation.subjects, Force
Imperial unit system, measurement_unit.measurement_system.length_units, Yard
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_lenght, Yard
Force, measurement_unit.dimension.units, KiloNewton
Imperial unit system, measurement_unit.measurement_system.weight_units, Hundredweight
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_volume, Gallon (Imperial)
Gill (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Dram, measurement_unit.mass_unit.measurement_system, Imperial unit system
Force, measurement_unit.dimension.si_base_unit, Newton
Rod, measurement_unit.distance_unit.measurement_system, Imperial unit system
Work (Mechanics), base.skosbase.skos_concept.broader_topic, Force
Imperial unit system, measurement_unit.measurement_system.length_units, League
Why slap them on the wrist with feather when you can belt them over the head with a sledgehammer., media_common.quotation.subjects, Force
Mile, measurement_unit.distance_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.length_units, Inch
Degree Fahrenheit, measurement_unit.temperature_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.force_units, Poundal
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_area, Square yard
Imperial unit system, measurement_unit.measurement_system.weight_units, Dram
Gallon (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.volume_units, Bushel (Imperial)
Fluid ounce (imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
m.0hn7rgm, dataworld.gardening_hint.last_referenced_by, Imperial unit system
force.noun.02, base.wordnet.synset.equivalent_topic, Force
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_area, Acre
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_mass, Pound
Quart (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
british imperial system.noun.01, base.wordnet.synset.equivalent_topic, Imperial unit system
Bushel (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.area_units, Square mile
Imperial unit system, measurement_unit.measurement_system.weight_units, Grain
Imperial unit system, measurement_unit.measurement_system.length_units, Nautical mile
Chain, measurement_unit.distance_unit.measurement_system, Imperial unit system
Force, measurement_unit.dimension.instruments, Force gauge
m.07q6y9t, base.wordnet.word_sense.sense, poundal.noun.01
Imperial unit system, measurement_unit.measurement_system.length_units, Fathom
m.07nf14g, base.ontologies.ontology_instance_mapping.freebase_topic, Force
Force, media_common.quotation_subject.quotations_about_this_subject, Whatever needs to be maintained through force is doomed.
Imperial unit system, measurement_unit.measurement_system.weight_units, Stone
Imperial unit system, measurement_unit.measurement_system.weight_units, Pound
Square foot, measurement_unit.area_unit.measurement_system, Imperial unit system
poundal.noun.01, base.wordnet.synset.word, m.07q6y9t
Force, media_common.quotation_subject.quotations_about_this_subject, A man convinced against his will; is of the same opinion still.
force unit.noun.01, base.wordnet.synset.hyponymy, poundal.noun.01
Pint (Imperial), measurement_unit.volume_unit.measurement_system, Imperial unit system
Force, media_common.quotation_subject.quotations_about_this_subject, Why slap them on the wrist with feather when you can belt them over the head with a sledgehammer.
Stone, measurement_unit.mass_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.length_units, Rod
Imperial unit system, measurement_unit.measurement_system.length_units, Furlong
Imperial unit system, measurement_unit.measurement_system.area_units, Square yard
Imperial unit system, measurement_unit.measurement_system.length_units, Link
Poundal, measurement_unit.unit_of_force.force_in_newtons, 0.138254954376
Force without forecast is to little avail., media_common.quotation.subjects, Force
Imperial unit system, measurement_unit.measurement_system.volume_units, Cup (Imperial)
Imperial unit system, user.avh.default_domain.ellerdale_topic.ellerdale_id, 0080-5e30
Fathom, measurement_unit.distance_unit.measurement_system, Imperial unit system
Force, measurement_unit.dimension.units, Newton
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_volume, Pint (Imperial)
Yard, measurement_unit.distance_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.volume_units, Gallon (Imperial)
Imperial unit system, user.movgp0.default_domain.measurement_system.unit_of_mass, Ounce
Force, measurement_unit.dimension.units, Kilogram-force
Force, media_common.quotation_subject.quotations_about_this_subject, Not believing in force is the same as not believing in gravitation.
Force is legitimate where gentleness avails not., media_common.quotation.subjects, Force
Imperial unit system, measurement_unit.measurement_system.volume_units, Tablespoon
m.07q6y9d, base.wordnet.word_sense.sense, poundal.noun.01
Imperial unit system, measurement_unit.measurement_system.length_units, Cable length
Imperial unit system, measurement_unit.measurement_system.length_units, Chain
Imperial unit system, measurement_unit.measurement_system.temperature_units, Degree Fahrenheit
Acre, measurement_unit.area_unit.measurement_system, Imperial unit system
poundal.noun.01, base.wordnet.synset.syntactic_category, Noun
Square yard, measurement_unit.area_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.weight_units, Long quarter
Force, media_common.quotation_subject.quotations_about_this_subject, Force is that which rules the actions without regulating the will.
Force, media_common.quotation_subject.quotations_about_this_subject, Force is legitimate where gentleness avails not.
Furlong, measurement_unit.distance_unit.measurement_system, Imperial unit system
noun.quantity, base.wordnet.lexical_name.synsets, poundal.noun.01
Cable length, measurement_unit.distance_unit.measurement_system, Imperial unit system
m.048kryb, dataworld.gardening_hint.replaced_by, Force
Force, media_common.quotation_subject.quotations_about_this_subject, Civilization is nothing more than the effort to reduce the use of force to the last resort.
poundal.noun.01, base.wordnet.synset.word, m.07q6y9d
Tablespoon, measurement_unit.volume_unit.measurement_system, Imperial unit system
Imperial unit system, measurement_unit.measurement_system.weight_units, Long ton

Answer: Imperial unit system