Work and Kinetic Energy and speed

AI Thread Summary
The kinetic energy of an object is defined by the equation K=(1/2)mv², indicating that both speed and mass influence energy. Performing work on an object changes its speed and, consequently, its kinetic energy. The discussion focuses on a sled starting from rest, analyzing the relationship between the net force acting on it and the change in kinetic energy as it moves a distance s, increasing its speed from v1 to v2. The net force Fnet can be expressed in terms of mass, distance, and initial and final speeds, while the net work Wnet is determined by the force and distance. Understanding these relationships is crucial for solving problems related to work and kinetic energy.
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The kinetic energy K of an object of mass m moving at a speed v is defined as K=(1/2)mv2. It seems reasonable to say that the speed of an object--and, therefore, its kinetic energy--can be changed by performing work on the object. In this problem, we will explore the mathematical relationship between the work done on an object and the change in the kinetic energy of that object.


Let us now consider the situation quantitatively. Let the mass of the sled be m and the magnitude of the net force acting on the sled be Fnet. The sled starts from rest.

Consider an interval of time during which the sled covers a distance s and the speed of the sled increases from v1 to v2. We will use this information to find the relationship between the work done by the net force (otherwise known as the net work) and the change in the kinetic energy of the sled.



1.Find the net force Fnet acting on the sled.?
(Express your answer in terms of some or all of the variables m, s, v1, and v2)
2.Find the net work Wnet done on the sled.?
(Express your answer in terms of some or all of the variables Fnet and s.)
 
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