A bead slide freely along a curved wire lying on a horizontal surface at constant speed as shown in Fig
a. Draw the vectors repesenting the force exerted by the wire on the bead at point A ,B and C
b. Suppose the bead in figure speeds up with constant tangential acceleration as it moves toward the right Draw the vector representing the force on the bead at point A B and C

Explanation

a. Because the speed is constant the only direction the force can have is that of the contripetal acceleration .The force is length at ( c) than at (A) because the radius at (c ) is smallar .There is no force at (B) because the wire is staight
b. In addition to the contripetal direction in (a), there are now tangential forces to provided the tangential acceleration . The tangential force is the same at all the there point because the tangential acceleration is constant