Answer the following question: Answer the following question given this paragraph: Figure 6.11 The frictional force supplies the centripetal force and is numerically equal to it. Centripetal force is perpendicular to velocity and causes uniform circular motion. The larger the F c , the smaller the radius of curvature r and the sharper the curve. The second curve has the same v , but a larger. Q: What force is perpendicular to velocity and causes uniform circular motion? A:

Available choices: A. centripetal torque. B. circular friction. C. tangential force. D. centripetal force.
Answer:
D.