The tensile strength of stainless steel produced by a plant has been stable for a long time with a mean of 72 kg/mm2 . a machine was recently adjusted and a sample of 10 items were taken to determine if the mean tensile strength has changed. the mean of this sample is 75.00 and the standard deviation of this sample is 2.56. a) at the 0.05 level of significance, is there evidence that the population mean of the tensile strength has changed from 72 kg/mm2 after the machine was adjusted. (15 points) b) find a 95% confidence interval for the mean of tensile strength after the machine was adjusted.

The metric unit of electrical power is the watt volt ampere ohm

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.