If a power source generates 5 w of power for 30 seconds, what's the total energy generated?

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

The least penetrating form of radiation is

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?