If there is to be no relative motion between the train and the edge of the platform, hov must the train move compared to the rim speed of the rotating platform?

=force × distance a. work b. velocity c. pressure d. momentum

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of