Question

A 1451 kg car is traveling at 48.0 km/h.

How much kinetic energy does it possess? K.E. =

1.67 x 105 J

9.65 x 105 J

1.28 x 105 J

3.48 x 105 J

Answer 1

would be a. since KE = 1/2 m*v^2

Answer 2

 KE  =  (1/2) · (1,451 kg) · (48 km/hr)² · (1000 m/km)² · (1 hr/3,600 sec)²

               =  (725.5) · (48 · 1000 · 1 / 3,600)²  (kg) · (km·m·hr / hr·km·sec)²

               =  (725.5) · ( 40/3 )²  ·  ( kg·m² / sec²)

               =    128,978  joules  (rounded)