Our goal in this activity is to explore the force that seems to pull an object down the ramp, that is, parallel to the ramp surface. But your force diagram does not have a force in this direction. Let's explore why. Notice that the force of gravity is neither parallel to, nor perpendicular to, the ramp surface. Try to add two more force vectors to your force diagram that break the force of gravity into components parallel to and perpendicular to the ramp surface. Part 2: Next, imagine that rather than sliding down the hill, the skateboarder holds onto a rope that is connected to a tree at the top of the hill, and that the force of the rope keeps the skateboarder in place. How would you modify your force diagram now? Add a force to your force diagram, this time directed parallel to the ramp surface but pointed up the ramp. Make the magnitude of the force such that it that would cause the skateboarder to be in equilibrium. IN mgsin 0 nig mgcos