Answer:
9.4 m/s
Explanation:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in kinetic energy of the system.
Therefore we can write:
[tex]W=K_f -K_i[/tex]
where in this case:
W = -36,733 J is the work done by the parachute (negative because it is opposite to the motion)
[tex]K_i = 66,120 J[/tex] is the initial kinetic energy of the car
[tex]K_f[/tex] is the final kinetic energy
Solving,
[tex]K_f = K_i + W=66,120+(-36,733)=29387 J[/tex]
The final kinetic energy of the car can be written as
[tex]K_f = \frac{1}{2}mv^2[/tex]
where
m = 661 kg is its mass
v is its final speed
Solving for v,
[tex]v=\sqrt{\frac{2K_f}{m}}=\sqrt{\frac{2(29,387)}{661}}=9.4 m/s[/tex]