Young David who slew Goliath experimented with slings before tackling the giant. He found that he could revolve a sling of length 0.600 m at the rate of 5.00 rev/s. If he increased the length to 0.900 m, he could revolve the sling only 3.00 times per second. (a) What is the speed of the stone for each rate of rotation

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.

How does an insulator stop the flow of an electric current? insulators convert electric energy to other forms of energy

Read the passage about bird food and bird watching. noted scientist dr. elsa birde described the effect of adding a mixture of dried apples and raisins to the previous feed of sunflower seeds, millet, thistle seed, and cracked corn in bird feeders in her yard. over three years, dr. birde observed that the new mixture increased the number of songbirds at her feeders, especially during the months of april and may. as she has done for several years, dr. birde recorded, at the same time each day, the number of birds at each of her four feeders. she noted that the third year using the mixture coincided with the largest increase. there was a twenty-five percent increase in the number of songbirds over times when this mixture was not used. dr. birde also noted that in the third year she used a specific ratio of the ingredients, carefully measuring, which she had not done in previous years. the third year also had a warmer than normal spring, and a construction project began in a neighborhood near dr. birde’s. dr. birde is now going to produce this formula for sale and advertise to customers that they may see the same twenty-five percent increase in songbirds at their feeders. dr. e. birde, journal of scientific bird feeding which scientific claim can be made? a. songbird numbers will increase due to the effects of climate change increasing global temperatures. b.songbirds appear more often in april and may. c. a combined ratio is the main reason songbird numbers increased. d. a study by dr. birde showed that the number of songbirds in her yard increased due to a modified food source.