Net Force Questions: Calculating Frictional Force

[jessical_x3]

Homework Statement

A student drags an object across a laboratory table at constant velocity using an applied force of 12 Newtons. Calculate the frictional force

2. a horizontal force of 15 Newtons pulls a 5 kg block along a horizontal surface. If the force produces an acceleration of 2 m/s(squared), what is the frictional force acting on the block?


(add FBD)

 

[jumbogala]

You need to show some of your own work, an attempt at the solution, before anyone will help you.