Answer these two questions: A man pulls a 6.00 kg box across a flat surface. He pulls with a constant force of 50.0 N upwards at an angle of 30.0° with the horizontal. The coefficient of kinetic friction between the box and the ground is 0.440. If the box starts from rest, and then the man begins to pull with a constant force, what will be the speed of the box 1.50 seconds after the man starts pulling? A 65.0 kg person rides on the roller coaster shown below, which has a vertical circular loop of radius 8.00 m. The roller coaster car is powered in such a way that it rotates through the loop at a constant rate of 1.30 rad/s. What is the normal force of the seat on the man?