A body moving at a speed of $20\,\text{m s}^{-1}$ has kinetic energy $E_k$. If its speed is raised to $80\,\text{m s}^{-1}$, what will its kinetic energy now be?
- A$4E_k$
- B$8E_k$
- C$12E_k$
- D$16E_k$
Physics 9702 · AS & A Level · Gravitational potential energy and kinetic energy