Under the combined action of forces F1, F2, F3 and F3, the object moves in a straight line at a constant speed. If the external force F1 is suddenly removed, the motion of the object is () A. It is necessary to make a uniform acceleration linear motion along the direction of F1. B. It is necessary to make a uniform deceleration linear motion along the direction of F1. C. It is still a uniform linear motion. D. it may be a linear motion or a curve motion

Under the combined action of forces F1, F2, F3 and F3, the object moves in a straight line at a constant speed. If the external force F1 is suddenly removed, the motion of the object is () A. It is necessary to make a uniform acceleration linear motion along the direction of F1. B. It is necessary to make a uniform deceleration linear motion along the direction of F1. C. It is still a uniform linear motion. D. it may be a linear motion or a curve motion

When F1 is removed, the resultant force of the residual force is equal, reverse and collinear with F1. When it is not collinear with the direction of speed, the object moves in a curve with uniform speed change, and when it is collinear, it moves in a straight line with uniform speed change, so D is correct