A bar 100 cm in length is subjected to an axial pull, such that the maximum stress is equal to 10^5 N! m^2. It's area of cross section is a bit 2 cm^2 over a length of the road 95 cm and for the middle 5 cm length it is only 1 cm^2. if E is a 200 GN/m^2,calculate the strain energy in the bar.

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

The speed of light can be used to measure the

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?