There is a certain work [b]W = m·g·h[/b] (g accelleration of gravity, g = 9,81 m/s²) necessary to lift a body with mass m in the gravity field of earth along a certain curve up to a height h.[br]This work W is not dependent on the specific form of the curve.[br][br][i]Hint:[/i] [br]Lifting a body gives a negative work. If the body is falling down the sign of the work is positive.[br][br][b]Task[/b][br]Change the height h and the shape of the curve by moving [color=#0000ff]point A, B, C and D[/color].[br]Check if there is always the same work necessary to lift a body up to the height h.[br]How does th work change if point D is on the x-axis or below?