at the instant t=0 a force F=kt (k is a constant) acts on a small body of mass m resting on a smooth horizontal surface.the time, when body leaves the surface is,
a)mgksinα b)ksinα/mg c)mgsinα/k d)mg/ksinα
From the question what I understand the force is applied at an angle from the horizontal. The above figure represent the situation. The block will leave the surface when the vertical component of the applied force will be equal to the blocks weight. Now vertical component of the force is . So we have
d) is the correct answer.