Jorge wishes to observe the progress of his vacuum pump in evacuating a tall bell jar for the purpose of demonstrating that sound waves do not travel in a vacuum. so, jorge places a mercury barometer inside the bell jar and follows the height of the mercury column as the pump chugs away. when he observes a height of 8.69 mm, what fraction of atmospheric pressure, expressed as a percentage, has jorge achieved in his bell jar? the density of mercury is 1.36 × 10 4 kg/m 3 and the standard atmospheric pressure is 1.01 × 10 5 pa. the acceleration g due to gravity is 9.81 m/s 2 . g