What's the difference between beam balance and spring balance?

A spring balance will give a different mass reading on the Moon from that on Earth. A beam balance however, will give the same reading.Explain why.

Beam Balance:

Beam balance measures mass.

Mass is the amount of matter the object has.

The S.I. unit of mass is kg


Spring Balance:

Spring balance measures weight not mass.

Disadvantage: It requires gravity to measure.

The S.I. unit of weight is newton (N).

That is why when we are in outer space, we become lighter-there is less gravity!

Mass remains constant while weight is dependent on the gravitational pull of the planet. Mass only changes with a change in matter that results in a change of volume.

Mass remains constant throughout. Only weight changes with gravitational acceleration. Mass will only change with a change in the volume of matter in the body.

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)