Block on Incline Plane QT Movie (908K) A block is pushed up an incline plane by an force parallel to the incline plane. There is friction between the block and the incline plane, and an applied force. Displayed are the resulting forces acting on the block as it moves up and down the incline plane as the applied force is varied. Block on an Incline Plane IP Simulation

Force of Friction on a Block QT Movie (256K) A varying horizontal force is applied to a block resting on a rough surface. Displayed are the various forces acting on the block as it move along the surface. Force of Friction on a Block IP Simulation

Block on the Wall QT Movie (296K) A block is pressed against a vertical wall by a force applied to the block. The applied force is varied to examine the motion of the block. Block on Wall IP Simulation and Block on the Wall Problem

Air Drag on a Cyclist QT Movie (608K)
A cyclist produces a constant force to propel himself and his bicycle along. The force he produces is determined by the maximum speed he can reach when there is air resistance. If he starts from rest his speed will reach a terminal velocity when the force he produces is equal to his air drag. Air Drag on a Cyclist Problem - Air Drag on a Cyclist IP Simulation

Tension on a Spring-Scale QT Movie (660K)
Two cords attached to the ends of a spring scale. The other ends of the cords pass over two pulleys and are connected to two 1 kg weights so that the scale is suspended horizontally and the weights hang vertically. What does the scale read? Shown is physical demonstration of the answer.

Sliding Block accelerated by a Hanging Block (440K)
A block that is resting on horizontal surface with friction is connected to a hanging block by a inflexible cord passing over a frictionless pulley. Initially the blocks is held in place by an external force. After the external force is removed the system accelerates. See Sliding Block accelerated by a Hanging Block Problem- and the IP Simulation.

Pushing Stacked Blocks (320K)
Two blocks are stacked on top of each other and set on a horizontal table top. A changing horizontal force is applied to the bottom block to see if the bottom block can be made to slip out from underneath the top block. There is friction between all surfaces. See Pushing Stacked Blocks Problem- and the Pushing Stacked Blocks IP Simulation.