Reading and Note Taking Guide Motion and Energy

Kinetic Energy

Kinetic energy is the energy of motion. An object that has motion - whether it is vertical or horizontal motion - has kinetic energy. There are many forms of kinetic energy - vibrational (the free energy due to vibrational movement), rotational (the energy due to rotational motion), and translational (the energy due to motion from ane location to some other). To continue matters elementary, we will focus upon translational kinetic energy. The amount of translational kinetic energy (from here on, the phrase kinetic free energy will refer to translational kinetic energy) that an object has depends upon two variables: the mass (m) of the object and the speed (5) of the object. The post-obit equation is used to represent the kinetic energy (KE) of an object.

KE = 0.5 • m • v²

where grand = mass of object

5 = speed of object

This equation reveals that the kinetic energy of an object is straight proportional to the square of its speed. That means that for a twofold increase in speed, the kinetic energy will increment by a factor of four. For a threefold increase in speed, the kinetic energy will increase past a factor of nine. And for a fourfold increase in speed, the kinetic energy will increase by a factor of sixteen. The kinetic free energy is dependent upon the square of the speed. Every bit information technology is oftentimes said, an equation is not merely a recipe for algebraic trouble solving, but also a guide to thinking about the relationship between quantities.

Kinetic free energy is a scalar quantity; it does not have a direction. Unlike velocity, dispatch, force, and momentum, the kinetic energy of an object is completely described by magnitude alone. Similar work and potential energy, the standard metric unit for kinetic energy is the Joule. Every bit might be implied by the above equation, 1 Joule is equivalent to 1 kg*(m/s)^2.

1 Joule = 1 kg • grand²/south²

We Would Similar to Advise ...

How does a car's speed (and thus its kinetic energy) affect the distance that would be required for it to restriction to a finish? Interact, Explore, and Learn the answer to this question with our Stopping Distance Interactive. You can discover it in the Physics Interactives section of our website. The Stopping Distance Interactive allows a learner to explore the effect of speed upon the stopping distance of a toy automobile.

Check Your Agreement

Use your agreement of kinetic energy to answer the post-obit questions. Then click the button to view the answers.

1. Determine the kinetic energy of a 625-kg roller coaster car that is moving with a speed of 18.three thousand/s.

2. If the roller coaster auto in the above problem were moving with twice the speed, and then what would be its new kinetic free energy?

3. Missy Diwater, the former platform diver for the Ringling Brother'southward Circus, had a kinetic free energy of 12 000 J just prior to hitting the saucepan of water. If Missy's mass is forty kg, then what is her speed?

iv. A 900-kg compact car moving at sixty mi/hr has approximately 320 000 Joules of kinetic free energy. Approximate its new kinetic energy if it is moving at 30 mi/hour. (HINT: employ the kinetic energy equation as a "guide to thinking.")

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Source: https://www.physicsclassroom.com/class/energy/u5l1c.cfm

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