What is a half-life? A. the amount of time it takes for 25% of a radioactive isotope sample to decay
B. half of the time it takes for an organism to die
C. the amount of time it takes for a radioactive isotope to become stable
D. the amount of time it takes for half of a radioactive isotope sample to decay

Which subatomic particle has a negative charge

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

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.