As shown in the figure, the uniform rectangular thin plate with mass m = 1kg and length L = 0.8m is still on the water table, and its right end is flat with the edge of the table. The dynamic friction coefficient between the plate and the table is μ = 0.4. The horizontal force F = 5N is used to push the thin plate to the right to make it turn down the table, and the work done by force F is at least (G is taken as 10m / S2) () A. 1JB. 2JC. 1.6JD. 4J

According to Newton's second law, the solution of F - μ mg = MA1 is A1 = 1m / S2. When decelerating, the solution of gravity, supporting force and sliding friction is A2 = - 4m / S2

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