The total amount of energy in the universe never changes, but the amount of energy available for work at any given moment varies tremendously What best explains this change in available energy?
O A Energy can only be created through nuclear reactions
OB Energy is continually changing from one form into another.
O
C Energy is always transferred as heat.
OD. Energy is always converted with 100 percent efficiency

How are momentum and impulse related? impulse is a whim to do something, while momentum keeps it going impulse is another name fore instantaneous momentum the impulse acting on and object is equal to the change of momentum it causes. the impulse that acts on and object is the momentum that results.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.