A 10-Kilogram Block Is Pushed Across a Horizontal Surface with a Horizontal

Multiple Choice

A 10-kilogram block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block in meters per second per second is

A) 10.
B) 5.
C) 1.
D) 2.
E) none of these