The diagram shows an electromagnet made with copper wire, a steel nail, and a 1.5 V battery. Which change would make this electromagnet weaker?

A. Reverse the direction of the battery

B. Rap more coils around the nail

C. Replace the steel nail with a wooden stick

D. Replace the battery with a 3V battery

Correct answer is C

You carry a 7.0-kg bag of groceries 1.2 m above the ground at constant speed across a 2.7m room. how much work do you do on the bag in the process? (a) 157j (b) 0.00j (c) 185j (d) 82j

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.