In base alla tabella delle densità (prima colonna) riportata a fianco se della cenere cade su un secchio contenente nafta galleggia o va a fondo? E se mettessi una chiave di ottone sopra ad un becker contenente mercurio, la chiave galleggia o va a fondo?

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Which statement is true? a) the work done to lift an object 6 meters is greater than the gravitational potential energy it gains. b) the work required to push an object is less than the work required to pull an object the same distance. c) the work required to raise an object to a height is equal to the gravitational potential energy the object gains. d) the work done against gravity to lift an object straight up is greater than the work required to roll it up a ramp.