Answer:
Elastic potential energy into kinetic energy
Explanation:
Initially the energy is stored inside the spring, which is compressed. This form of energy is called elastic potential energy, and its formula is
[tex]U=\frac{1}{2}kx^2[/tex]
where k is the spring constant, which gives the 'strength' of the spring, while x is the compression/stretching of the spring with respect to its equilibrium position.
When the spring unwinds, it returns to its equilibrium position, so x becomes zero and the potential energy converts into another form of energy, which is related to the motion of the car (in fact, the car starts moving). This form of energy is called kinetic energy, and its formula is
[tex]K=\frac{1}{2}mv^2[/tex]
where m is the mass of the car and v is its speed.
