Substance X is placed in a container with substance Y. Both substances are fluids. Substance X initially sinks to
the bottom of the container. After five minutes of being
heated on a hot plate, substance X becomes less dense
than substance Y.
What will most likely happen next?
Substance X will rise due to convection.
O Substance Y will rise due to convection.
Substance X will rise due to radiation.
Substance Y will rise due to radiation.

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.

Chameleons catch insects with their tongues, which they can rapidly extend to great lengths. in a typical strike, the chameleon's tongue accelerates at a remarkable 220 m/s2 for 20 ms, then travels at constant speed for another 30 ms.

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