A 5.00-kg object moves clockwise around a 50.0 cm radius circular ...

[mikaylakyoung]

A 5.00-kg object moves clockwise around a 50.0 cm radius circular path. At one location, the speed of the object is 4.00 m/s.
 
  When the object next returns to this same location, the speed is 3.00 m/s.
  (a) How much work was done by non-conservative forces as the object moved once around the circle?
  (b) If the magnitude of the above non-conservative forces acting on the object is constant, what is the minimum value of this magnitude?

Question 2

A convex mirror has
 
  A)
 
  no focal length.
  B)
 
  a positive or negative focal length depending on the object position.
  C)
 
  a positive focal length.
  D)
 
  a negative focal length.
  E)
 
  a positive or negative focal length depending on the object size.

[ebe]

Answer to Question 1

(a) -17.5 J
(b) 5.57 N

Answer to Question 2

D

[mikaylakyoung]

Thanks for the timely response, appreciate it

[aruss1303]

Gracias!