Question

(Engineering) The current / varies as the electromotive force E and inversely as the resistance R. If in a system, a current of 20A flows through a resistance of 20 ohms with an electromotive force of 100V, find the currect that 150V will send throu+gh the system.

(Navigation) The amount of coal used by a steamship travelling at a uniform speed varies jointly as the distance traveled and the square of the speed. If a steamship uses 45 tons of coal travelling 80 mi at 15 knots, how many tons will it use if it travels 120 mi at 20 knots?

Answer 1

Since current varies directly as E, 1.5(100)V will send 1.5(20) = 30A

c = kdv^2
Since 120/80 = 3/2 and 20/15 = 4/3, the new c will be (3/2)(4/3)^2 * 45 = 120 tons

Answer 2

Ok. I got the same answers. Thanks.

Answer 3

Thanks to the both of you for helping.

Answer 4

the current I varies directly as the electromotive force E and inversely as the resistance R. If a current of 30 amperes flows through a system with 16 ohms resistance and electromotive force a 120 volts,find the current when the current when the system with 20 ohms resistance and electromotive force of 200 volt.the current I varies directly as the electromotive force E and inversely as the resistance R. If a current of 30 amperes flows through a system with 16 ohms resistance and electromotive force a 120 volts,find the current when the current when the system with 20 ohms resistance and electromotive force of 200 volt.