1) An object, having a weight of 20 N, moves from point A to point B on a smooth surface of a path in a three-dimensional space. The x-y- and z- coordinates of the points are given respectively in meters: A (0; 3; 3), B (6; 5; 0). The speed of the object at point A is 18m/s and the force [F=2ri+ 3y^2 j+ z k] N is acting on the object during the motion. What is the speed of the object at point B?
2) The acceleration of a 2kg body along straight line is expresses as a -0,002 v^2 m/s^2. The initial velocity of the body at the beginning of its motion is vo. How far does the body travel until its velocity becomes the half of its initial velocity?
3) A 105gr-baseball moves in the horizontal direction to the right with a velocity of 18m/s. After the baseball is hit with a 3kg bat, it moves to the left, in a direction 20\deg from the horizontal with a velocity of 38m/s. If the duration of interaction between the baseball and the bat is 0.028s, what is the average impulsive force (its magnitude and direction) applied on the baseball by the bat?
Take g9.81 m/s^2 when you need to use.