Why is the work output of any real machine less than the work needed to operate it?

work is gained due to friction

work is lost due to friction

friction reduces the work input

If Air Traffic Control advises that radar service is terminated when the pilot is departing Class C airspace, the transponder should be set to code?

Would the density of a person be the same on the surface of the earth and on the surface of the moon?

Does the weight of a vehicle get heavier with speed? & why?

A 10.0 V battery is connected to a 120-ohm resistor. Ignoring the internal resistance of the battery Calculate the power delivered to the resistor.

Describe three safety procedures you should always follow when conducting a scientific investigation.

A student measured the mass of a rock to be 19.8 grams; the actual mass was 18.6 grams. What was the student's percent deviation?

The height of the Washington Monument is measured to be 170 m on a day when the temperature is 35.0ºC. What will its height be on a day when the temperature falls to - 10.

Which of the following is a way humans have impacted the rainforest, but not the tundra?

Explain what happens when a massive star ends its life as a supernova.

Freckles are a dominant trait in humans. Both of the girls have the genotype FF for freckles. If either one marries a man with no freckles, what are the chances that their children will have freckles? A) 0% B) 50% C) 75% D) 100%