Susan was traveling in an airplane. She looked out of a window in the airplane and saw clouds in the sky. Why could Susan see clouds through the window of the airplane? A.
Most of the light hitting the window was transmitted when it passed through the window.
B.
Most of the light hitting the window was reflected off of the window instead of passing through it.
C.
Most of the light hitting the window was refracted when it passed through the window.
D.
Most of the light hitting the window was absorbed by the window instead of passing through it.

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?

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.

Asmall grinding wheel has a moment of inertia of 4.0×10−5 kg⋅m2 . what net torque must be applied to the wheel for its angular acceleration to be 150 rad/s2 ?