Center mass Kinetic Energy?

In summary, the change in kinetic energy of the center of mass of the coyote/rocket combo is equal to 1/2 times the mass of the combo times the initial velocity squared. This is because the final velocity is 0 and the change in kinetic energy is equal to the difference between the initial and final kinetic energy.
  • #1
pxp004
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Wiley Coyote and his Acme rocket, together having inertia of 1000 kg, are speeding after Roadrunner. Upon seeing a large brick wall in his path, Coyote tries to slow down. Unfortunately, he’s still going 5 m/s when he runs into the wall. The wall is not affected, but the rocket crumples (the coyote hangs on), such that the center of mass of the rocket/coyote travels forward 50 cm between striking the wall and coming to rest.

What is the change in kinetic energy of center of mass of the coyote/rocket combo?

Would you just use 1/2mv^2?

I know the center mass velocity equation but that doesn't seem to help. Change in KE would be Initial - Final. Final would be 0 so i just thought that the change in Kinetic would be 1/2mv^2. Is this right?
 
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welcome to pf!

hi pxp004! welcome to pf! :smile:

(try using the X2 button just above the Reply box :wink:)
pxp004 said:
Change in KE would be Initial - Final. Final would be 0 so i just thought that the change in Kinetic would be 1/2mv^2. Is this right?

yup! that simple! :biggrin:
 

1. What is center mass kinetic energy?

Center mass kinetic energy is the energy that an object possesses due to its motion. It is calculated by multiplying the mass of the object by the square of its velocity and dividing by two.

2. How is center mass kinetic energy different from regular kinetic energy?

Regular kinetic energy is the energy an object has due to its overall motion, while center mass kinetic energy specifically refers to the energy of an object's center of mass. This is important for objects with irregular shapes or multiple moving parts.

3. What are some real-world applications of center mass kinetic energy?

Center mass kinetic energy is important in many fields, including physics, engineering, and sports. For example, it is used in calculating the energy required for projectiles to penetrate certain materials, or the energy needed for vehicles to brake safely.

4. How is center mass kinetic energy related to momentum?

Center mass kinetic energy and momentum are closely related, as they both measure an object's motion. In fact, the formula for center mass kinetic energy can be derived from the formula for momentum by squaring the velocity and dividing by the mass.

5. Can center mass kinetic energy be negative?

No, center mass kinetic energy cannot be negative. Since both mass and velocity are squared in the calculation, the resulting value will always be positive. A negative value would imply that the object is moving in the opposite direction of its velocity, which is not possible.

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