The kinetic energy of the cart is 24 J.
Step-by-step explanation:
The acceleration of a given mass from rest to the velocity is known as kinetic energy. It gains energy from acceleration and remains in this state until the speed of the object changes.
The kinetic energy is the given by,
K.E = 1/2 mv^2
Given the mass m = 3 kg, v = 4 m / s.
K.E = 1/2
3
(4)^2
K.E = 24 J.