However, if the force is opposing the displacement, make sure you use a negative value for the force so that you get a result of negative work.Īnother tip for using the work equation is to pay careful attention to the force that is causing the displacement. For example, if the force and displacement have the same direction, both values will have the same sign so their product, the work, will be positive. When substituting values for force and displacement, you’ll want to make sure you use the right sign based on their direction. Applying the Work Equation Tips and Strategies for Using the Work Equation If it takes more time to perform the work, the power is less. The less time it takes to perform the work, the greater the power. The amount of work done on an object has nothing to do with the amount of time it takes to do that work. Both work and power depend on force and displacement. Since power is the rate at which work is done, the only difference between work and power is time. Work and power are closely related concepts with one important difference. For example, consider a box moving to the left pulled by a force at an angle as shown below.Įxplore Power on Albert The Difference Between Work and Power You will need to first determine the component of the force in the same direction as the displacement. Using the equation for work is a bit more complicated in situations where the force is applied at an angle relative to the displacement. For example, if a person exerts a 5\text of work on the box. We can calculate work using the following equation: The Work Equationīased on the equation above, you can calculate work by multiplying force and displacement. Interested in an Albert school license? The Equation for Work For example, when a baseball player slides toward home plate, the force of friction from the ground opposes his motion and the work done by friction on the baseball player is negative.Ĭheck out this video from GPB Education for more examples of work and how it can be positive or negative. A common force that typically does negative work is friction. Work is negative when the force and displacement are in opposite directions. The dogs in the previous example are doing positive work on the sled because the slide is moving in the same direction as the force the dogs are applying by pulling forward. Work is positive when the force and displacement are in the same direction. Work can be either positive or negative depending on the direction of the force relative to the direction of the displacement. If you push as hard as you can on a building, you may get exhausted from the force you apply but you’re not actually doing work because the building doesn’t move. It’s important to know that in order for work to be done, the force must cause displacement and move the object. When a force acting on an object causes the object to move, we say that work is done on the object.įor example, the dogs in the picture below are doing work on the sled because they are applying a force that pulls the sled forward. In physics, work is defined as the change of energy in a system caused by a force applied over a displacement.
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