Chapter 30, Problem 93P

A pendulum has a 0.4-m-long cord and is given a tangential velocity of 0.2 m/s toward the vertical from a position 0 = 0.3 rad. Part A Determine the equation which describes the angular motion. Express your answer in terms of the variable t. Express coefficients in radians to three significant figures. ΜΕ ΑΣΦ vec (t)=0.3 cos (4.95t) + 0.101 sin (4.95t) Submit Previous Answers Request Answer × Incorrect; Try Again; 6 attempts remaining

Part A ■Review The uniform 150-lb stone (rectangular block) is being turned over on its side by pulling the vertical cable slowly upward until the stone begins to tip. (Figure 1) If it then falls freely (T = 0) from an essentially balanced at-rest position, determine the speed at which the corner A strikes the pad at B. The stone does not slip at its corner C as it falls. Suppose that height of the stone is L = 1.2 ft. Express your answer to three significant figures and include the appropriate units. ? ft VA 10.76 S Submit Previous Answers Request Answer × Incorrect; Try Again; 6 attempts remaining

Consider the circuit shown in the figure. The battery has emf ε = 69 volts and negligible internal resistance. The inductance is L = 0.4 H and the resistances are R 1 = 12 Ω and R 2 = 9.0 Ω. Initially the switch S is open and no currents flow. Then the switch is closed. After leaving the switch closed for a very long time, it is opened again. Just after it is opened, what is the current in R 1?