Suppose that you lived on a planet with Earth’s mass (5.97×1024 kg) but only half its radius (that is, a radius of 3,189 km instead of 6,378 km). Suppose, too, that your own mass was 75 kg. a. What would your weight be on the surface of this hypothetical planet? (State your answer in both newtons and in pounds.)

b. What would the acceleration due to gravity be on the surface of this made-up planet? (State your answer in newtons per kilogram and compare it to the value on Earth’s surface.)

As newton's first law states a object in motion stays in motion

Since the pully is a simple machine so the mechanical advantage is a 1

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)