2021/2022 5.
You are provided with some 1 penny coins, an electronic balance and a measuring
cylinder which already contains some water as shown below.
Describe in detail what you would do and what measurements you would make in
order to calculate the density of the metal used for 1 penny coin.
(5 marks)

Ireally don’t know

Pe = 1/2k(x)^2  and .05n/m = .05x10^-9m = x 

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)