Cars are notorious energy wasters. Most cars run on gasoline. Th e chemical energy stored in gasoline is transformed into motion in the
engine. Engine motion is then transferred to the drive wheels, making
the car move.
In a typical engine, only about one-quarter of the chemical energy
in the gasoline is converted into mechanical work by the engine. By
the time that energy is transferred into the drive wheels, less than
20 % of the gasoline’s energy is actually used to move the car. Th e
remaining energy is lost through such things as hot exhaust gases
(fumes), heating the water in the car’s cooling system, overcoming
friction in the car’s moving parts, vibration, and sound (Figure 2).
Make a list of other machines that have energy loss? What energy is lost?

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.

Marcella is a four-year-old girl who is a victim of emotional child abuse. based on the child and family services improvement and innovation act of 2011, which action should the government take for marcella? a. the state should arrest marcella’s abuser. b. the state should find a home for marcella as soon as possible. c. the state should enforce stricter laws in the area where marcella resides. d. the state should provide medical assistance to marcella.

An electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field