An ultra-high-energy cosmic ray proton is detected with a kinetic energy of 2.5×1019 eV2.5 \times 10^{19}\text{ eV}2.5×1019 eV. A small toy car of mass 80 g has kinetic energy equal to that of this cosmic ray proton.
What is the speed of the toy car?
5.0 m s−15.0\text{ m s}^{-1}5.0 m s−1
7.1 m s−17.1\text{ m s}^{-1}7.1 m s−1
10 m s−110\text{ m s}^{-1}10 m s−1
100 m s−1100\text{ m s}^{-1}100 m s−1
