The calculation of momentum involves
mass and velocity
mass and acceleration
motion
distance and velocity

So since the snail is moving at 3.6  miles per hour you multiply by 5280 to change it into feet per hour. so you get 36*528 ft per hour. since there are 3600 seconds in an hour, you divide 36*528 by 3600. so simplifying we get 528/100 which is 5.28 ft per second

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)

I’m not sure about this question