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.

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.