A man lifts a 3.1 kg stone vertically with his hand at a constant velocity of 2.1 m/s. What is the magnitude of the total force of the man's hand on the stone?

You are pulling a suitcase through the airport at a constant speed. The handle of the suitcase makes an angle of 34.4° with respect to the horizontal direction. If you pull with a force of 30.0 N parallel to the handle, what is the force of friction acting on the suitcase?