Sample Exam used on Jan 31, 2011 for DLRC Review in Physics 71

1. SECOND EXAM

23. 26. Three balls having the same masses m are released simultaneously from the same elevation with speeds v but with different orientations: θ =90° , θ=45°, θ=30°. Neglecting air resistance, which of the following quantities will be the same for the three balls at the highest point of their motion? a. Total Mechanical energy b. Potential energy c. Kinetic energy d. momentum e. speed

26. A. B. C. D. E.

33. For the next three problems: The angular position of an industrial fan changes with time as θ=π t 2 rad/s 2 . The fan has a radius of 0.250 m. 36. What is the distance travelled by a point on the rim in 2.00 s? 37. What is the average angular velocity between t 1 = 0 s and t 2 = 3 s? 38. What is the instantaneous angular acceleration?

36. 41. Hayden (H) and Kho (K) are riding in a Flying Fiesta, EK stuff. Their positions relative to the axis of rotation are indicated in the figure. If for instance the swing ride moved at a constant angular velocity, which of the following is TRUE? a. θ H < θ K b. ω H < ω K c. v H < v K d. atan ,H < atan ,K e. Both C and D