You can protect something from a laser weapon by O using reflective material
O using semiconductors
O using superconductors
O moving faster then the laser

Explain why electric current cannot exist if a current doesn't have a voltage source.

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.

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) ! : )