A 1.60 kg , horizontal, uniform tray is attached to a vertical ideal spring of force constant 200 N/m and a 265 g metal ball is in the tray. The spring is below the tray, so it can oscillate up-and-down. The tray is then pushed down 14.7 cm below its equilibrium point (call this point A) and released from rest. Now I know Fspring will be equal to total weight at the point where ball leaves the tray but I want to learn why? both Fspring and total weight are downwards at that point and I don't understand where do we know it.

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

-the first industrial use of geothermal energy began near pisa, italy in late 18th century

-in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power

-with the above experiment, the first geothermal plant in usa started in 1922 with a capacity of 250 kilowatts

-however, in 1946 first ground-source geothermal heat pump installed at commonwealth building in portland, oregon

-during the 1960’s, pacific gas and electric began operation of first large scale geothermal power plant in san francisco, producing 11 megawatts

-in 1973, when oil crisis began many countries began looking for renewable energy sources and by 1980’s geothermal heat pumps (ghp) started gaining popularity in order to reduce heating and cooling costs

-as effect of climate change started showing results, governments of various countries joined hands to fight against it, for which kyoto protocol was signed in japan in 1997, laid out emission targets for rich countries and required that they transfer funds and technology to developing countries, 184 countries have ratified it

hope this

third one with arrows on top of each other going the same direction