The angular velocity of a process control motor is (13−12t2) rad/s, where t is in seconds. part a at what time does the motor reverse direction? express your answer to two significant figures and include the appropriate units. tt = nothing nothing request answer part b through what angle does the motor turn between t =0 s and the instant at which it reverses direction? express your answer to two significant figures and include the appropriate units. δθδ θ = nothing nothing request answer

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?