Why do people not use permanent magnets when making electric motors with large capacity to create magnetic fields?

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?

Question 1 of 15 2 points when doing science as inquiry, you should have some idea of what you think the final result will be. o a. true o b. false submit

Aball is thrown vertically upwards from the top of a tower with a speed of 100m/s. it strikes the pound near the base of the tower after 25sec . the height of the tower is