Question

I know it's a lot, but I would really really appreciate any help. It is my study guide and I am hoping with your help I can manage to do good on the exam

7) A rock of mass m is tied to a string and spun in a vertical circle. When the rock is at the bottom the tension force is X. At the top, the rock is moving at the same speed, and the tension in the string a. Is equal to X b. Is greater than X c. Must equal mg d. May be zero. 8) Which of the following scenarios provides a mechanical advantage of 2? 30 deg a. ll only b. II and III c. I and II d. I only 9) Using a simple machine that provides mechanical advantage a. Allows a task to be performed with less work b. Allows a task to be performed with less force C. Increases the power available to do a task d. is unrelated to the conservation of energy 10) If an object is thrown up in the air, its kinetic energy a. Is conserved b. Is first positive, then zero, then negative c. First decreases, and then increases d. Increases at a uniform rate 11) If two objects of masses m, and m2 have an identical kinetic energy a. m, must have greater speed if m <m2 b. The masses must have identical speeds cm, must have greater speed if mm2 d. They both must also have the same momentum

Answer 1

on top pm2)/R tension T Thop Toottore M2 at lowest poin . mela e sol" :- There are three forces acting on rock is weight mg je wi) centrifugal force mpose Now at topmost pont Timg = m Lev To make mg B at lowest point out ng+ me from equation and o we can say hence option a. is incorrect. Again equation and we can say that Por is conect Again from equations if merug option d is also correct. Walton Top Toottor Tratto Thoo once option Trop =0 hence then