An ice skater starts spinning (without friction) at an angular speed of oo. as she pulls her arms and legs tightly against her body, her angular speed gradually increases to 30 (a) calculate the skater's final period of rotation (t). express your answer in terms of her initial period (t). show your working. (b) determine the skater's final moment of inertia (i). express your answer in terms of her initial moment of inertia (1). provide a reason to support your answer. (e) which one of the following statements is true about the skater? provide a reason to support your answer. a. both her angular momentum and her rotational kinetic energy increased. b. her angular momentum increased, but her rotational kinetic energy remained constant c. her angular momentum remained constant, but her rotational kinetic energy increased. d. both her angular momentum and her rotational kinetic energy remained constant.

Learning goal: to understand newton's 1st law. newton's principia states this first law of motion: an object subject to no net force maintains its state of motion, either at rest or at constant speed in a right line. this law may be restated as follows: if the sum of all forces acting on an object is zero, then the acceleration of that object is zero. mathematically this is just a special case of the 2nd law of motion, f⃗ =ma⃗ , when f⃗ =0. when studying newtonian mechanics, it is best to remember the 1st law in two ways: if the net force (i.e., sum of all forces) acting on an object is zero, the object will keep moving with constant velocity (which may be zero). if an object is moving with constant velocity, that is, with zero acceleration, then the net force acting on that object must be zero. complete the following sentences to see if you can apply these ideas. part a if a car is moving to the left with constant velocity, one can conclude that