The force$-$compression graph of a hypothetical spring is shown below.

$($a$)$ How much work is done in compressing the spring $0\mathrm{.}60m?$

$($b$)$ What is the potential energy stored in the spring when compressed this amount?

$($c$)$ A $5\mathrm{.}0kg$ toy car is placed on a level, frictionless surface against the spring when compressed $0\mathrm{.}60m,$ and the spring is released. The other end of the spring is fixed. Determine the velocity of the car when it has moved a distance of $0\mathrm{.}20m.$