#1.) If the force of gravity on a human is 539 N determine the mass of the human.

#2.) Draw a free body diagram for the following situation:
a.) A 0.15 kg running shoe is pushed to the right, with a constant velocity, across a wet concrete floor with an applied force of 3.5 N.

b.) Calculate the normal force exerted by the concrete onto the running shoe.

#3.) Draw a free body diagram of a boat being pulled at an accelerated rated by a truck down a highway.