NEED ANSWERED ASAP!! will give brainliest!
What is the kinetic energy of an 8.0 x 104 kg airplane flying at 600.0 km/h?
A. 1.44 x 1010 J
B. 2.9 x 1010 J
C. 2.2 x 109
D. 1.1 x 109 J

Respuesta :

AL2006
The kinetic energy of any moving object is

            K.E.  =  (1/2) (mass) (speed)² .
 
To use this simple formula, the 'mass' has to be in kilograms,
and the 'speed' has to be in meters-per-second. 

You can see that we have a slight problem that has to be cleaned up:
The speed in the question is given in "kilometers per hour", but we'll
need it in "meters per second".  So let's convert that right now: 

       (600 km/hour) x (1 hour / 3600 seconds) x (1000 meters / km)

    =    (600 x 1 x 1000 / 3600)    (km-hour-meters / hour-second-km)

    =              166.67  meters/second .

Now we're ready to plug numbers into the formula for K.E.

                  (1/2) (mass) (speed)²

            =    (1/2) (80,000 kg) (166.67 m/s)²

            =           (40,000 kg) (27,777.8 m²/s²)

            =                1,111,111,111  kg-m²/s²

            =                 1.1... x 10⁹  Joules   (choice D)