As shown in Figure 3,the internal resistance of the battery r=1.5Ω,R1=R2=R3=4Ω,R4=10Ω (a)When the key S1 and S2 are disconnected, the voltage meter read 4V, find the power emf.
(b)When the key S1 and S2 are closed,
(i)What is the reading of the voltmeter?
(ii)What is the reading of the ammeter?

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

Aa a of 22 m/s at an of 36.9 .be . a. b. c. (3)x y of? (3)go? (4) () it to to ?