Walter is making a list of energy transformations for a homework assignment. He needs at least one example in which electrical energy is transformed to mechanical energy. Which of the following transformations should he include?

turning on a radio
turning on a ceiling fan
turning on a light bulb
turning on a stove

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

Karen is running forward at a speed of 9 m/s. she tosses her sweaty headband backward at a speed of 20 m/s. the speed of the headband, to the nearest whole number relative to a stationary observer watching karen

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?