A bar magnet was placed underneath a sheet of paper where a pile of iron filings sits. In the presence of the energy stored in the magnetic field, the iron filings arranged themselves, creating lines of force. How do the energy and the lines of force change when a stronger bar magnet is used

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) ! : )