A 60-Watt bulb illuminates a surface a distance d away with an illuminance of 2400 lux. What would be the illuminance on a surface a distance 2d away (i. e. twice as far away) when illuminated by a 30-Watt bulb?

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?

The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot