Knowing that a force p of magnitude 50 kn is required to punch a hole of diameter d = 20 mm in an aluminum sheet of thickness t = 5 mm, determine the average shearing stress in the aluminum at failure.

Your answer is c. explanation: plasma  is the fourth state of matter, derived from the gaseous state of matter.  plasma  can contain free  electrons  and/or  ions. while  plasma is never neutral, it can either be positively or negatively charged.  gases, however, are electrically neutral.

British cologoinst admisitrion

45 is the correct answer