The picture below shows a toy car in the process of rolling down a ramp. At point X, the kinetic energy is 50 Joules (J), and the potential energy is 30 J.

What is the total energy in the system once the car reaches the bottom of the ramp?
A
20 J, because the energy in the system cannot change form but can be created and destroyed

B
80 J, because the energy in the system can change form but cannot be created or destroyed

C
30 J, because the potential energy is the only energy at the bottom of the ramp

D
50 J, because the kinetic energy is the only energy at the bottom of the ramp

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

You win the lottery and decide to impress your friends by exhibiting a million-dollar cube of gold. at the time, gold is selling for $ 426.60 per troy ounce, and 1.0000 troy ounce equals 31.1035 g. -how tall would your million-dollar cube be? en cm

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above