QUESTIONS: 1) The linear (tangential) velocity of a point on a rotating body will always be to the radial direction along the body. a) Perpendicular b) Parallel c) Equal d) Greater than 2) If an object spins at constant angular velocity, the tangential acceleration will always be: a) Clockwise b) Zero c) Counterclockwise3) The axis of rotation will always be at what angle from the plane of rotation? (Try using right hand rule imitate a rotation). a) 30" b) 45" c) 60\" d) 90" 4) The angular displacement, angular velocity, and angular acceleration of a rotating body and the linear distance, tangential velocity, and tangential acceleration of a point on the body are related, respectively, by the a) Arc length b) Radius of the circular path taken by the point c) Shape of the body cl) Distance from the axis of rotation to the point e) Both b and d 56. A wheel spins at a constant angular velocity of 6.5 rad/s about its axle for 4.3s. 5) What is the angular displacement (in radians)? 6) What is the angular displacement (in degrees)? Hint: You can soive this problem using the originai information given or the answer to Q5 rounded to the nearest 1/100. 7) If the diameter of the wheel in the previous problem is 0.75 m, then what is the linear velocity (in m/s) of a point on the outer rim of the wheel? 8) A tee ball player swings a bat with angular velocity of 1000 degrees/s. After impact, the baseball leaves the bat with a linear velocity of 50 m/s. How far from the axis of rotation did the baseball come into contact with the bat (in meters)? Note: Remember to account for units. 9-13. A pitcher accelerates a softball from a tangential velocity of 1.2 m/s (clockwise motion} to 15.9 m/s (counter clockwise motion) over 0.27 s and then releases the ball. Assume angular acceleration is constant throughout the motion, and the pitcher's arm is 0.56 meters long. 9) Calculate the instantaneous angular velocity of the pitcher's arm at the start of the acceleration (in rad/s}. 10) Calculate the instantaneous angular velocity of the pitcher's arm at release (in rad/s). 11) Assume the answers to Q9 and Q10 are -3 rad/s and +30 rad/s, respectively. Calculate the average angular acceleration of the pitcher's arm over this interval (in rad/52). 12) Assume the answer to Q11 is 120 rad/52. Calculate the tangential acceleration of the ball at the instant of release (in m/sZ). 13) Calculate the centripetal acceleration of the ball at the instant of release (in m/sz). Use the values given in the original problem to solve. 14) If the angular velocity of a rotating body is negative but decreasing, the tangential acceleration of a point on the body points in the same direction as tangential velocity. a) True b) False 15) In the image below, a rigid body (blue dot) at a distance of 1m from a fixed axis (open circle) rotates 45". There is also a small mass (red dot) located half way along the radius. What statement is FALSE regarding relative values for each of the dots during the movement? a) The angular displacements are equal b) The angular velocities are equal c) The blue dot has a smaller linear displacement are d) The red dot has a smaller linear velocity 0\17) When a person standing in neutral flexes their right shoulder so that their arm is horizontal with the ground, the center of gravity (mass) will a) Remain in the same location c) Move superior and to the right b) Move inferior and posterior d) Move superior and anterior 18) When examining the gait cycle for one leg during human walking, we can break up a single stride into a) stance phase and progression phase b) stance phase and double support c) single support and single progression d) stance phase and swing phase 19) Which statement is FALSE? a) Centripetal acceleration always has a direction that is perpendicular to tangential velocity b) Centripetal acceleration will always increase if radius increases for constant in c) Centripetal acceleration will always point CCW if angular velocity is increasing d) Tangential acceleration will always point CW if angular velocity is decreasing 20) Based on the angular position (0) curve on the right, what angular velocity (w) value is highest? 2 a) Average w between t = 0.8 and t = 2.8 s b) Instantaneous w at t = 1.6 s 1.5 c) Average w between t = 0 and t = 1.2 s d) Instantaneous w at t = 2.8 s 0.5 Angular Position (degrees) 0 -0.5 -1 -1.5 0 0.4 0.8 1.2 1.6 2 2.4 2.8 Time (s)