An old mining tunnel disappears into a hillside. you would like to know how long the tunnel is, but it's too dangerous to go inside. recalling your recent physics class, you decide to try setting up standing-wave resonances inside the tunnel. using your subsonic amplifier and loudspeaker, you find resonances at 5.0 hz and 6.4 hz , and at no frequencies between these. it's rather chilly inside the tunnel, so you estimate the sound speed to be 331 m/s . based on your measurements, how far is it to the end of the tunnel?

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?

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

The ability to make things happen is also called a. heat b. force c. matter d. energy