Which force makes an object free fall?

wind

gravity

fluid forces

friction

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

Which of the following statements are evidence that gases do not always behave ideally? check all that apply.? a. co2 gas becomes dry ice (solid co2) at 1 atm and –78.5 °c. b. when two gases are mixed, they follow dalton\'s law of partial pressures. c. at 4 k and 1 atm, helium is a liquid. d. it is impossible to compress a gas enough so that it takes up no volume.