Acement block accidentally falls from rest from the ledge of a 80.6-m-high building. when the block is 10.8 m above the ground, a man, 2.10 m tall, looks up and notices that the block is directly above him. how much time, at most does the man have to get out of the way?

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.

If the specific heat of a metal is 0.850 j/g °c, what is its atomic weight?