Group Activity #4 Tuesday, September 25, 2018 Example 1: Find the velocity, acceleration, and speed of a particle given by the position function r(r) 2 costi+3sint j atr=0. Example 2: A baseball is hit 4 feet above the ground leaves the bat with an initial speed of 98 ft/sec at an angle of 450 is caught by an outfielder at a height of 3 feet. a. How far was the ball hit from home plate? b. What is the maximum height of the ball? c. How fast was the ball traveling when it impacts the outfielder's glove? CONCEPTS 1. Explain how to demonstrate experimentally that force is a vector. (a) How could you show that a force resolves into the proper components regardless of its magnitude or direction? (b) How or directions? 2. (a) Identify the forces acting on each of the bodies shown in the illustration at upper right. (b) What is the reaction force corresponding to each of these forces? 3. Set a block on an inclined plane and adjust the angle of tilt until the friction equation (Theory 3.) is valid. Also demonstrate the situation where the inequality is valid? 4. (a) Identify the forces acting on each of the bodies shown in the illustration at lower right. (b) What is the reaction force corresponding to each of these forces? (c) Which of these forces produces a torque about the axis indicated by O? (d) What is the direction of each of these torques? 5. Explain how the center of mass of a sheet of material can be found by using a plumb bob and suspending the sheet successively from several points. 6. How is center of mass related to torque? What is the difference between center of mass and center of gravity? P m m2 37° W1 W3 ICE table as illustrated at right and ights and the angles the W2 60°