Given data:
* The mass of the object suspended from the edge of a table is 2.6 kg.
* The acceleration of the system is,

Solution:
The force acting on the system is,

where m_1 is the mass of the cart and m_2 is the mass of the object suspended, and a is the acceleration of the system,
The only force acting in this case is the weight of the object suspended from the edge of a tabel.
Thus, the force acting on the system is,

where g is the acceleration due to gravity,
Substituting the known values,

Thus, the mass of the cart is 4.1 kg.