## Find the magnitude of the work done by the force of friction. answer in units of j.

## Work done by friction

Consider how you felt this morning. Do you feel energized and ready to go when you wake up? Or did you feel sleepy, dragged your feet, and couldn’t seem to get up? We often discuss our energy levels, but what does that really imply? And where do you get your energy?

We also refer to living things as having energy; think of an energetic dog or a fast-moving fish. Is it possible for a tree to have energy? Is there any energy in your car? What do you think about a lightbulb? Or the chair you’re actually seated in? What about a rock that’s lying around on the ground outside?

When a force is applied to an object, it usually causes the object to accelerate in the direction of the net force. We change the amount of energy in an object by making it accelerate. The ability to work or complete a task is referred to as energy.

We give a ball the opportunity to fly through the air and create a dent in the dirt when we throw it by adding force to it when we throw it. Without the energy transfer from your hand to the ball, the ball would not have been able to do such stuff.

## Find work done given force vector and distance vector

The friction between two surfaces converts kinetic energy into thermal energy when they move relative to each other (that is, it converts work to heat). The use of friction produced by rubbing pieces of wood together to start a fire is an example of how this property can have drastic consequences. As motion with friction occurs, such as when a viscous fluid is agitated, kinetic energy is converted to thermal energy. Wear is another significant consequence of many forms of friction, which can result in performance degradation or component damage. The science of tribology includes friction as a part.

Friction is beneficial and necessary for providing traction and promoting movement on ground. For acceleration, deceleration, and changing direction, most land vehicles depend on friction. Sudden traction failure can result in a loss of control and an accident.

Friction is not a fundamental force in and of itself. Inter-surface adhesion, surface roughness, surface deformation, and surface pollution all contribute to dry friction. Because of the complexity of these interactions, it is impossible to calculate friction from first principles, necessitating the use of analytical methods for study and theory creation.

### A 1.6-kg block on a horizontal surface is attached to a spring

The term “work” has a different meaning in daily life than it does in physics. Only the part of an applied force that is parallel to the motion works on an object in physics. A individual carrying a heavy book, for example, is not doing any work on the book.

Calculate the work performed on a box if it is dragged (text5m) along the ground by a force of (F=text20text N) at an angle of (text60)(text°) to the horizontal.

A force of (text10) (textN) is applied to drive a block across a frictionless surface for a rightward displacement of (text5,0) (textm). (text20) (textN) is the weight of the block (vecF g ). Calculate the amount of work performed by the following forces: natural force, weight (vecF g), and applied force.

After a displacement of (text5,0) (textm) to the right, a frictional force of (text10) (textN) slows a moving block to a stop. (text20) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) (textN) ( Calculate the amount of work performed by the following forces: normal force, weight, and frictional force.

### A 7.80-g bullet moving at 575 m/s penetrates a tree trunk to a

Work is characterized as a form of energy in physics. When a force acts on something that moves from one location to another, work is created. Forces can shift with position, and displacements can take several different paths between two points. We first define the dot product of these two vectors as the increment of work dW performed by a force (vecF) acting through an infinitesimal displacement d(vecr):

Figure 1: (PageIndex1) Work is described by vectors. At one point along the path between A and B, the force acting on a particle and its infinitesimal displacement are seen. The dot product of these two vectors is infinitesimal work; the integral of the dot product along the direction is absolute work.

Since the definition of the dot product for work can be expressed more clearly in terms of magnitudes and angles, we prefer to express it in terms of the magnitudes of the vectors and the cosine of the angle between them. The dot product could have been expressed in terms of the different components implemented in Vectors. The x- and y-components in Cartesian coordinates, or the r- and (varphi)-components in polar coordinates, were these in two dimensions; in three dimensions, it was just the x-, y-, and z-components. Which option is more practical depends on the circumstances. In other words, the work performed by a force acting over a displacement can be expressed as a result of one component acting parallel to the other component, as seen in Equation 7.1. Because of the properties of vectors, it makes no difference if you take the component of the force parallel to the displacement or the component of the displacement parallel to the force—the effect is the same.