Points I don't need them anymore

What did pavlov initially notice about the animals in his original research after conditioning took place?

A(t)=(t−k)(t−3)(t−6)(t+3) is a polynomial function of tt, where kk is a constant. given that a(2)=0a(2)=0, what is the absolute value of the product of the zeros of aa?

Ateacher attaches a ball to a meter long string and whirls it around in a horizontal circle at constant speed. the teacher explains that the string is what makes the ball go in a circle. why is the string necessary? a) the string is needed to apply a torque to the ball. b) the string is needed to push on the ball to get it up to speed. c) circle motion requires an inertia which is provided by the string. d) circle motion requires a force to give it a centripetal acceleratio