Why is Newton’s cradle (Newton’s balls) described as an “almost-ideal” closed system? Explain your reasoning in one or two sentences.

Aseries circuit consists of a resistor with r = 20 ? , a capacitor with c = 0.01 f, and a decaying battery with e = 300e? 5t. if the initial charge is 0, find the charge as a function of time t

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.

An automobile steering wheel is shown. what is the ideal mechanical advantage? if the ama is 8, what is the efficiency of the steering wheel?