## Kinetic Energy

Kinetic energy

is the free energy of motion. An object that has move – whether it is vertical or horizontal motion – has kinetic energy. There are many forms of kinetic free energy – vibrational (the free energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the free energy due to motion from 1 location to another). To go on matters simple, we will focus upon translational kinetic energy. The amount of translational kinetic energy (from hither on, the phrase kinetic energy volition refer to translational kinetic energy) that an object has depends upon 2 variables: the mass (m) of the object and the speed (v) of the object. The following equation is used to represent the kinetic free energy (KE) of an object.

**KE = 0.5 • g • five ^{2}
**

where

**g**

= mass of object

**v**

= speed of object

This equation reveals that the kinetic energy of an object is directly proportional to the square of its speed. That ways that for a twofold increase in speed, the kinetic energy will increase by a factor of four. For a threefold increment in speed, the kinetic energy will increase by a factor of nine. And for a fourfold increase in speed, the kinetic free energy will increase by a gene of sixteen. The kinetic free energy is dependent upon the square of the speed. As information technology is often said, an equation is not only a recipe for algebraic problem solving, only also a guide to thinking most the relationship between quantities.

Kinetic energy is a scalar quantity; it does not have a direction. Unlike velocity, dispatch, force, and momentum, the kinetic free energy of an object is completely described by magnitude alone. Like work and potential energy, the standard metric unit of measurement for kinetic energy is the Joule. As might be unsaid by the to a higher place equation, 1 Joule is equivalent to 1 kg*(m/due south)^2.

**1 Joule = 1 kg • grand**

^{ii}/s^{2}

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**We Would Similar to Advise …**

How does a auto’southward speed (and thus its kinetic energy) impact the distance that would be required for it to brake to a stop? Interact, Explore, and Larn the reply to this question with our Stopping Distance Interactive. You can find information technology 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 car.

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**Check Your Understanding**

Use your agreement of kinetic energy to reply the following questions. Then click the push to view the answers.

1. Determine the kinetic energy of a 625-kg roller coaster automobile that is moving with a speed of 18.3 one thousand/south.

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

3. Missy Diwater, the onetime platform diver for the Ringling Brother’s Circus, had a kinetic energy of 12 000 J just prior to hitting the bucket of water. If Missy’s mass is xl kg, and then what is her speed?

iv. A 900-kg meaty automobile moving at lx mi/hr has approximately 320 000 Joules of kinetic energy. Estimate its new kinetic energy if it is moving at thirty mi/hr. (HINT: use the kinetic free energy equation as a “guide to thinking.”)

## If the Speed of an Object Doubles Its Kinetic Energy

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