This gives you the negative work (or Wout). The area under the curve between two points is the work done. delta U (3/2)nR (delta T), delta T is 0, so the right side is equal to zero because you are multiplying the (3/2)nR by 0. The work done is positive if the force and displacement have the same direction, and the work done is negative if they have opposite direction.Įnergy: A quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalentįorce-displacement graph: A graph of the force applied on the y-axis, and distance moved on the x-axis.The work done by a force is zero if the displacement is either zero or perpendicular to the force.Work is the transfer of energy by a force acting on an object as it is displaced.Practice Exam 3 B/B Section Passage 1 Question 4 Practice Exam 3 B/B Section Passage 1 Question 1 Official Guide C/P Section Passage 2 Question 7 Physics Question Pack Passage 13 Question 82 Formula: Power Work done (J) / Time taken (s) Simplified formula: P W.D. Physics Question Pack Passage 13 Question 79 Power is mathematically defined as the work done divided by the time taken. Physics Question Pack Passage 7 Question 45 To calculate the work done when we lift a weight or mass vertically some distance, we’ll use the integration formula for work, where W is the work done, F(x) is the force equation, and a,b is the starting and ending height of the weight or mass. Work can also be calculated in these systems from force-displacement graphs.Ĭoronary heart disease and blood pressure This is true for work done by a constant force (like the examples shown here), as well as work done by a variable force. Work done by an elastic force, for example, follows the equation W = k sx 2/2, where k s is the spring constant of the force and x is the displacement. The work can be calculated as the area under the force-displacement graph. Energy is transferred to the briefcase and could, in turn, be used to do work. Work is done on the briefcase by carrying it upstairs at a constant speed because there is necessarily a component of force F in the direction of the motion. The person moving the briefcase horizontally at a constant speed does no work on it and transfers no energy to it.ģ. Following this form of energy equation, specific work done by the system on the surroundings is regarded as positive, while specific work done on the system. No energy is transferred to or from the briefcase. A person holding a briefcase does no work on it because there is no motion. Hookes Law provides us with an equation that can be used to calculate the exact magnitude of the force required to compress or stretch a spring by some. The work done by the force F on this lawnmower is Fdcosθ.Ģ. W is work, F is the magnitude of the force on the system, d is the magnitude of the displacement of the system, and θ is the angle between the force vector F and the displacement vector d.ġ. The work done on a system by a constant force is the product of the component of the force in the direction of motion times the distance through which the force acts.
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