Energy and Machines

Rotational kinetic energy and conservation of energy was the order of the day for B, C and F Blocks. Rotational kinetic energy is another form of mechanical energy and should rightfully be included when considering conservation of energy. When working problems, remember the tips that we discussed in class and just be very careful and systematic when setting up your equations. Tomorrow, we begin a discussion of simple machines, mechanical advantage and efficiency...

...which was what E Block investigated in lab today. You worked with levers and pulleys, two machines that rely on torque to function, and analyzed how repositioning the effort force for levers and changing number of supporting ropes for pulleys affected mechanical advantage. Effectively, how did changing distance affect the amount of force needed to raise your load or resistance. Machines cannot give us more work out than we put in, but they can increase our effort force or distance. If effort force is increased, the force acts over a small distance. If effort distance is increased, it only generates a small output force. Both factors cannot be multiplied simultaneously. We'll discuss the lab tomorrow and begin our discussion of simple machines, using your results to highlight our talk.