38. A softball pitcher that is 5ft 10in tall with an arm length of 71cm, uses a windmill pitch to send a What was the angular velocity (rad/s) of ball right before it left ball sailing to a batter at 29m/s. the pitcher's hand?

3. A typical hard disk in a desktop computer is a uniformly solid, 400 gram disk 3.5 inches in diameter, and takes 70 milliseconds to spin from rest up to a frequency of 7200 revolutions per minute (r.p.m.). A) What is the period of the disk in seconds when it's at its final spinning rate? B) What is its angular speed in rad/s when it's at its final spinning rate? C) Assuming it is constant throughout this spin-up process, what is the angular acceleration of the disk in rad/s?? D) How many revolutions does the disk go through during this spin-up process? E) Which is bigger, the centripetal force felt by a dust particle stuck to the edge of the disk halfway through its spin-up or the centripetal force felt by an identical dust particle stuck halfway to the edge of the disk when it's at full speed?

What is the angular momentum L, of a 0.300-kg tetherball when it whirls around the central pole at 70.0 rpm and at a radius of 135 cm? L₂= x10 TOOLS kg-m²/s

3. The figure to the right shows a rod that is connected to a frictionless table through a pin-labeled by A -placed through the center of it. (You are looking down on the table.) The rod has mass m and length l. Although the rod is initially at rest, it can rotate freely (without friction) about the pin. A small particle with mass m/3, and moving with an initial velocity vo vo collides with the end of the rod. After the collision the mass stops moving, and the rod starts rotating with angular velocity w. I would strongly recommend that you draw a free body diagram for the rod in parts a and b. a. Linear momentum is not conserved for this collision. Explain in detail why. b. Angular momentum is conserved about the pivot. Explain in detail why. c. What is w? Express it in terms of vo, and l. d. Is energy conserved in the collision? Justify your answer by calculating the change in energy of the system in the collision. e. After a time T after the collision the rod will rotate around and…

6. A ceiling fan turns at a rate of 20 RPM what is its speed in radians per second, and the speed of a tip of a 50 cm fan blade in m/s?

Two identical spheres with m 3 kg each are rigidly attached to the rotating light rigid structure. The velocity of the spheres is v = 2 m/s. Determine the angular momentum about the axis of rotation. 5 13 0.3 m 0.2 m m' H, = 7.20 kg · O H, 1.80 kg· m2 %3D O H. 3.60 kg. m' H. = 6.00 kg .

3. After watching a video of Steph making 105 consecutive 3-pointers, an analyst wants to study his kinematics during shooting. At the specific instant in time, the following variables were measured: m Linear velocity of shoulder: V§ = + 0.1 ™ ƒ WW/E Angular velocity of wrist w.r.t. elbow: rad Angular velocity of elbow w.r.t. shoulder: = +2 WE/S S The upper arm is at 0 = 39° w.r.t. the horizontal axis. The angle between the upper arm and forearm is a = 86°. Length of upper arm: Lupp = 0.4 m Length of forearm: Lfore = 0.31 m What is the linear velocity of the wrist vw? PA DING W E rad = -8 k S m m Answer: Vw = +1.311 ™ î+ 1.168 ™ Ĵ k

2. Write a detailed solution. Identify the given quantities and unknowns. Label them properly.

7. A 0.25 kg bullet is fired with a velocity of 200 m/s into two spheres mounted on a shaft with a vertical axis of rotation (coming out of the page) the spheres rotate horizontally. Each sphere has a mass of 0.80 kg and can be treated as a point mass. The mass of the shaft can be ignored. The bullet hits one of the spheres at the angle shown and sticks to the sphere which starts at rest. 30° Axis Of Rotation a. Determine the linear momentum of the bullet. b. Determine the angular momentum of the bullet/spheres system after the bullet hits the sphere. (Remember, momentum is conserved so you can calculate the momentum of the system at any time as long as you include all of the pieces.) 0.50 m

A 97.5 kg97.5 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.55 rad/s1.55 rad/s. A monkey drops a 8.03 kg8.03 kg bunch of bananas vertically onto the platform. They hit the platform at 4545 of its radius from the center, adhere to it there, and continue to rotate with it. Then the monkey, with a mass of 21.1 kg21.1 kg, drops vertically to the edge of the platform, grasps it, and continues to rotate with the platform. Find the angular velocity of the platform with its load. Model the platform as a disk of radius 1.95 m1.95 m.