Question

What happens to its kinetic energy, when the speed of car gets doubled?

• A. It is quartered
• B. It is halved
• C. It is unchanged
• D. It is doubled
• E. It is quadrupled

Answer 1

The correct option is E It is quadrupled

Kinetic energy of car $K=\frac{1}{2}m{v}^2$

Now the speed of car is doubled i.e $v^{\prime }=2v$

$\therefore$ New kinetic energy $K^{\prime }=\frac{1}{2}m(v^{\prime }{)}^2=\frac{1}{2}m(2v{)}^2=4K$