Two identical positive charges are separated by a distance of 2.4 × 10−10 m. If the charges repel each other with a force of 5.7 × 10−9 N, what is the magnitude of each positive charge? A.
2.8 × 10−8 C
B.
1.9 × 10−19 C
C.
1.2 × 10−5 C
D.
3.6 × 10−20 C

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?

Three resistors are connected in series across a 15-v power supply. if the potential drops across resistors 1 and 2 are 4.1 volts and 3.1 volts, what is the exact potential drop (in volts) across resistor 3?