A stationary 1.67-kg object is struck by a stick. The object experiences a horizontal force given by F = at ‐ bt^2, where t is the time in seconds from the instant the stick first contacts the object. If a = 15 N/s and b =20 N/s^2, what is the impulse of the force over the period 0 s t = 3.0 s?

Suppose that a comet that was seen in 563 a. d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

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

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z