A toy sled with weight of 16 N is sliding down a ramp that makes an angle of 35° with the ground.
The coefficient of kinetic friction between the toy sled and the ramp is 0.30.
1. In a coordinate system where the x-axis is parallel to the ramp and the y-axis is perpendicular to
the ramp, what are the components of the toy sled's weight?
2. How large is the normal force acting on the toy sled?
3. What is the magnitude and direction of the force of friction acting on the toy sled?
4. In a coordinate system where the x-axis is parallel to the ramp and the y-axis is perpendicular to
the ramp, how large is the net force acting on the toy sled along the x-axis?
5. Using Newton's second law, calculate the acceleration of the toy sled as it moves down the ramp.
Answers
Answer:
By the end of the section, you will be able to:
Describe the general characteristics of friction
List the various types of friction
Calculate the magnitude of static and kinetic friction, and use these in problems involving Newton’s laws of motion
When a body is in motion, it has resistance because the body interacts with its surroundings. This resistance is a force of friction. Friction opposes relative motion between systems in contact but also allows us to move, a concept that becomes obvious if you try to walk on ice. Friction is a common yet complex force, and its behavior still not completely understood. Still, it is possible to understand the circumstances in which it behaves.
Static and Kinetic Friction
The basic definition of friction is relatively simple to state.
Friction
Friction is a force that opposes relative motion between systems in contact.
There are several forms of friction. One of the simpler characteristics of sliding friction is that it is parallel to the contact surfaces between systems and is always in a direction that opposes motion or attempted motion of the systems relative to each other. If two systems are in contact and moving relative to one another, then the friction between them is called kinetic friction. For example, friction slows a hockey puck sliding on ice. When objects are stationary, static friction can act between them; the static friction is usually greater than the kinetic friction between two objects.
Static and Kinetic Friction
If two systems are in contact and stationary relative to one another, then the friction between them is called static friction. If two systems are in contact and moving relative to one another, then the friction between them is called kinetic friction.