A 2 KG box is put on the surface of an inclined plane at 30 degrees with the horizontal. The box is pulled by a 40 N force applied horizontally relative for the inclined plane. The surface of the inclined plane is assumed to be frictionless. A) Determine the acceleration of the box.
B) Determine the force exerted by the inclined plane on the box.

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)

Yup your right can give me more detail