One well-known application of density is determining whether or not an object will float on water. If the object's density is less than the density of water, it will float; if its density is less than that of water, it will sink.In fact, submarines dive below the surface of the water by emptying their ballast tanks
Answer:
c. 1600J
Explanation:
The loss in potential energy of the boy is given by:

where
m = 40 kg is the mass of the boy
g = 9.8 m/s^2 is the acceleration of gravity
is the total change in the height of the boy (4 metres + 2 cm due to the compression of the spring)
Substituting, we find

4ms I'm just guessing by the way
Answer:
Complete Circuit
Explanation:
A circuit is defined as a completed path for voltage to flow from a source of voltage through a load and back to the source. A complete circuit or path is often referred to as a(n) ? circuit. Before current can flow in a circuit, the circuit must be closed. 100% right