Respuesta :
There are four (4) that can be identify in all forces that acting on the object. Normal force, \vec{n} is a component that is perpendicular to the surface of contact. Air resistance, \vec{D} is a type of friction and it is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. Kinetic friction force, \vec{f}_k is μk times the normal force on an object and it is expressed in units of Newtons. Weight, \vec{w} is a force caused by gravity and it is measured in Newtons.
The forces acting on a car which is skidding to a stop are its weight due to gravity, a normal force coming from the ground, and the friction force due to the relative movement between the tires and the ground. Theoretically, we should also consider the friction force due to air viscosity, however practically we can neglect this force since it's contribution is very small in comparsion to the others (specially at low speeds).
Further explanation
By making the free body diagram of the car, we can observe 3 things:
- The car has a certain mass, therefor due to the effect of gravity, it will have certain weight pointing towards the ground. It is important to remember that the weight always points downwards, even if the car would be on an inclined plane.
- Even though weight pulls the car down, the floor excerts a force over the car upward which keeps it in place. This is called the normal force and it is always perpendicular to the ground.
- Due to the roughness of the tires and the concrete, there will be a friction force do the relative movement between them. This friction force always goes in the opposite direction in which the car is moving (so if the car is heading to the right, the friction force aims towards the left, thus slowing it down).
As a reference you can check the attached image, which shows how the forces would be in case the car would brake on a horizontal street. In case the car would be slowing on a floor which is not horizontal, like on a hill, the forces would have different directions.
Learn more
- Forces acting on a body: https://brainly.com/question/4230804
- Difference between kinetic and static friction: https://brainly.com/question/1714663
- Newton's second law: https://brainly.com/question/254316
Keywords
Forces, acceleration, friction
