Problem A block is dropped onto a spring that is attached to the ground. The block follows the pathway shown in the diagram below and passes through positions 1-3. The block is dropped at position 1, has fallen to the spring without compressing the spring at position 2, and has been momentarily stopped by the compressed spring at position 3. The height of zero (y=0y=0y, equals, 0) is marked on the diagram below.
Click each dot on the image to select all answers that apply. Choices:
KKK
U_gU
g
​
U, start subscript, g, end subscript
U_sU
s
​
U, start subscript, s, end subscript
The diagram shows a block's pathway as it falls onto a spring. Position 1 is at the moment the block is dropped above the spring. Position 2 is just before the block hits the spring. Position 3 is at the block's lowest point where the spring momentarily stops the block.

Select the types of energy present (non-zero) for the block-Earth-spring system as the block is at each of