Arace car is moving with a velocity of 144 km/h the driver applies the brakes and the car comes to a halt in 12 seconds what is the average acceleration of the car during those 12 seconds

Average acceleration = (change in speed) / (time for the change)

Change in speed = (speed at the end) - (speed at the beginning)

Change in speed = (zero) - (144 km/hr)

Change in speed = -144 km/hr

(-144 km/hr) x (1,000 m/km) x (1 hour/3600 sec) = -40 m/s

Time for the change = 12 seconds

Average acceleration = (-40 m/s) / (12 s)

Average acceleration = -3.33 m/s² (about 1/3 of a 'G')

! 55 !  

write a paragraph or story to explain the transformation between potential and kinetic energy as shown in your picture or model.  

you should have at least 5 complete sentences with a main idea and supporting details.  

you must include the following words:  

potential energy

kinetic energy

mechanical energy

conservation of energy

dude, this is hard lol : ))