The distance between point A and the current-carrying wire is d, and the strength of the magnetic field is H. If the distance between point B and the wire is 2d, what is the strength of the magnetic field a point B?

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )