My buddy and i are planning a shore dive. we’re descending onto a very gradual slope that begins at 5 metres/15 feet, so our descent and ascent will be a gradual part of swimming out and back underwater. we have similar cylinders filled to 200 bar/3000 psi. we plan: • 50 bar/500 psi reserve. • 20 bar/300 psi for our safety stop. • to turn the dive when we’ve used one-third of the air available to use on the dive. this means we should head back when either of our spgs read

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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)

D=m/v m=d*vd=densitym=massv=volumed(ether)=0.71 gr/cm³=0.71 gr/ mlv=130 mlm=d*vm=0.71 gr/ml*(130 ml)=92.3 gm=92.3 g