An object of mass 20 kg is raised vertically through a distance ...

[londonang]

An object of mass 20 kg is raised vertically through a distance of 8.0 m above ground level. Using g = 10 m/s2 what is the potential energy of this object at this position?
 
  A) 1.6 J
  B) 16 J
  C) 160 J
  D) 1600 J
  E) 16000 J

Question 2

A 50.0-N box is sliding on a rough horizontal floor, and the only horizontal force acting on it is friction. You observe that at one instant the box is sliding to the right at 1.75 m/s and that it stops in 2.25 s with uniform acceleration.
 
  What magnitude force does friction exert on this box? A) 3.97 N
  B) 8.93 N
  C) 38.9 N
  D) 50.0 N
  E) 490 N

[frankwu0507]

Answer to Question 1

D

Answer to Question 2

A

[londonang]

Excellent

[fatboyy09]

TYSM