How Does Hitting a Wall Affect Kinetic Energy?

[pxp004]

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?

 

[tiny-tim]

welcome to pf!

hi pxp004! welcome to pf!

(try using the X² button just above the Reply box )

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!