QuickCheck 3.21 A toy car moves around a circular track at constant speed. It suddenly doubles its speed - a change of a factor of 2. As a result, the centripetal acceleration changes by a factor of A. 1/4 B. 1/2 C. No change since the radius doesn't change. D. 2 E. 4 Slide 3-116QuickCheck 3.19 A car is traveling around a curve at a steady 45 mph. Is the car accelerating? A. Yes C B. No Slide 3-108Reading Question 3.2 A is positive if is directed A, is positive if is directed A. Right, up B. Left, up C. Right, down D. Left, down Slide 3-6\f\fReading Question 3.1 The of a vector is always a positive quantity. A. x-component B. y-component C. Magnitude D. Direction Slide 3-4Reading Question 3.4 The acceleration vector of a particle in projectile motion A. Points along the path of the particle. B. Is directed horizontally. C. Vanishes at the particle's highest point. D. [S directed down at all times. E. 15 zero. 5H. 3-10 3 of 32 Reading Question 3.4 Reading Question 3.5 The acceleration vector of a particle in projectile motion The acceleration vector of a particle in uniform circular motion A. Points along the path of the particle. B. Is directed horizontally. A. Points tangent to the circle, in the direction of motion. C. Vanishes at the particle's highest point. B. Points tangent to the circle, opposite the direction of D. Is directed down at all times. motion. E. Is zero. C. Is zero. D. Points toward the center of the circle. E. Points outward from the center of the circle. Slide 3-11 Slide 3-12Reading Question 3.3 The acceleration of a cart rolling down a ramp depends on A. The angle of the ramp. B. The length of the ramp. C. Both the angle of the ramp and the length of the ramp. D. Neither the angle of the ramp or the length of the ramp. Slide 3-8