1) 4°C : It has the highest density as shown on the graph.
2) Water expands when it freezes, making it less dense than just water.
3) The ice would sink to the bottom, then the rest of the water would freeze as well, the entire lake/river/whatever will freeze eliminating the organisms that live there.
The answer would be a.
a chemical change is a change to the chemical makeup of a substance so if the bonds are unchanged it would be a characteristic of a physical change
<span>Suppose you mixed two chemicals in the lab until you could not tell the two apart. After some time passed, a white powder formed which would not dissolve, and settled on the bottom. The mixture was first homogeneous then heterogeneous. </span>
A body of mass m has weight
F = GMm/r²
on the surface of the Earth, where G is the universal gravitational constant, M is the mass of the Earth, and r is it's radius.
If the weight is to be halved, then we have
1/2 F = 1/2 GMm/r² = (1/√2)² GMm/r² = GMm/(√2 r²)
so the distance between the body and the planet's center needs to be
√2 × 6.4 × 10⁶ m ≈ 9.1 × 10⁶ m
Answer:
v_average = 15 m / s
Explanation:
The average speed can be found in two ways,
* taking the distance traveled and divide it by the time spent
* taking the velocities in each time interval and then finding the weighted average by the time fraction
v_average = 1 / t_total ∑ 
vi ti
Let's apply this last equation
Total time is
t = t₁ + t₂
t = 10 + 10 = 20 min
v_average = 10/20 10 + 10/20 20
v_average = 10/2 + 20/2
v_average = 15 m / s
