From the information given, the lab cart has a mass of 0.5 kg and the student exerts a force of 3N on it.
We use the formula F = MV
Where F = Force, M = mass and V = velocity
In our case, F = 3N (or 3 Kg m/s²) , M= 0.5 kg , V is unknown.
F= MV → MV = F → V = F / M
V = 3 kg m/s² / 0.5 kg
V= 3 / 0.5
V = 6 m/s²
Therefore the acceleration of the cart 6 m/s²
