The gravitational force between the Sun (mass = 1. 99 Ă— 1030 kg) and Mercury (mass = 3. 30 Ă— 1023 kg) is 8. 99 Ă— 1021 N. How far is Mercury from the Sun? 6. 98 Ă— 1010 km 6. 98 Ă— 107 km 4. 87 Ă— 1013 km 4. 87 Ă— 1024 km.

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.