A 1.2-kg mass is projected up a rough circular track (radius = ...

[itsmyluck]

A 1.2-kg mass is projected up a rough circular track (radius = 0.80 m) as shown. The speed of the mass at point A is 8.4 m/s, and at point B, it is 5.6 m/s. What is the change in mechanical energy between A and B caused by the force of friction?
 
   

   
  a.
  2.7 J
   
  b.
  8.8 J
   
  c.
  4.7 J
   
  d.
  6.7 J
   
  e.
  19 J

Question 2

A 1.2-kg mass is projected down a rough circular track (radius = 2.0 m) as shown. The speed of the mass at point A is 3.2 m/s, and at point B, it is 6.0 m/s. What is the change in mechanical energy done on the system between A and B by the force of friction?
 
   

   
  a.
  8.9 J
   
  b.
  7.3 J
   
  c.
  8.1 J
   
  d.
  6.6 J
   
  e.
  24 J

[nmyers]

Answer to Question 1

c

Answer to Question 2

c

[itsmyluck]

Thanks for the timely response, appreciate it

[cdmart10]

Excellent