Write a program using the pthreads api that prints "hello, world! " from four threads it creates and prints the ids of the threads along with in the format "hello, world! from thread id : 0" from each of the threads. you can use a global variable to declare the number of threads to be created and set that to 4 for this assignment.

Fluids at rest possess no flow energy. a)- true b)- false

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?