Jacob and sophia are playing with a merry-go-round on a playground. the merry-go-round can be modeled as a flat disk with massm= 223.0kg and radiusr= 3.3 m that freely rotates horizontally without frictionabout its center axis. when the merry-go-round is already spinning at23 rotations per minute, jacob exerts a constant forcefj= 12.3 ntangent to the outer edge of the merry go round in the direction of themerry-go-round’s rotation. at the same time sophia puts her foot ata distancer= 3.1 m from the center, which exerts a constant force offrictionfs= 21.2 n. how long will it take for the merry-go-round tocome to a stop?

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

Aprisoner is forced to go into one of three rooms, but he can choose which room. the first room is ablaze with fire. the second one is rigged with explosives that will go off as soon as he enters. the third contains a pair of lions who haven't eaten in years. which room should he choose to survive?