The object moves in a straight line at a constant speed under the action of common point forces F1, F2 and F3. The correct value of these three forces is () A. 15N、5N、6NB. 1N、2N、10NC. 3N、4N、5ND. 1N、6N、3N

The object moves in a straight line at a constant speed under the action of common point forces F1, F2 and F3. The correct value of these three forces is () A. 15N、5N、6NB. 1N、2N、10NC. 3N、4N、5ND. 1N、6N、3N

A. 15N, 5N, 6N, the maximum resultant force of the first two forces is 20n, the minimum resultant force is 10N, it is impossible to be 6N, so a is wrong; B, 1n, 2n, 10N, the maximum resultant force of the first two forces is 3N, the minimum resultant force is 1n, it is impossible to be 10N, so B is wrong; C, 3N, 4N, 5N, the maximum resultant force of the first two forces is 7n, the minimum resultant force is 1n, it is possible to be 5N, so C is correct