9 A large 1 kg weight is suspended from the ceiling by a lin

9) A large 1 kg weight is suspended from the ceiling by a linear spring. In static equilibrium, the weight is hanging about 1 meter above the floor. The weight is then pulled down until it is positioned right above two fresh eggs (~1mm above the eggs). When the weight is released it is pulled upwards by the spring and then falls back down under the influence of gravity. On the way down it a. reverses direction of travel well above the eggs b. reverses direction precisely as it reaches the eggs c. makes a mess and crashes into the eggs

Solution

The answer is b). reverses direction precisely as it reaches the eggs because the total energy of the system is always conserved, At the lowest point (ie just above the egss) the mass has maximum spring energy, zero potential energy and zero kinetic energy. As the mass moves upwards its spring energy converts into potential energy and kinetic energy but as soon as it comes back towards the eggs, because of conservation it gains all its pring energy back and again its potential energy and kinetic energy become zero.