A cart of mass \(2.0 \text{ kg}\) is initially moving with a velocity of \(1.0 \text{ m/s}\) in the \(+x\)-direction along a frictionless horizontal track. A net force \(F\) is applied to the cart in the \(+x\)-direction for \(4.0 \text{ s}\), as shown in the force-versus-time graph. During this \(4.0 \text{ s}\) interval, the cart travels a total distance of \(27 \text{ m}\). What is the velocity of the cart at \(t = 4.0 \text{ s}\)?