1. since Beatrice is applying force to the box, she is doing work
2. formula is work = force x displacement
3. displacement = 2 meters, force = 40 N
work = 40 x 2 = 80 Joules
Answer: ice is less dense than liquid water. If ice was more dense, Earth would freeze.
Explanation: There are many reasons why life on Earth depends on the characteristics of water. One could discuss hydrogen bonds and its role as a solvent, but the unusual property of water is is the change in density with change in temperature. Water is densest at 4 degC, which is why ice floats - it is less dense than cold water (it melts quickly in warm water, so density isn’t impotant at higher temperatures). Most liquids are less dense than the solid, frozen form. If this was the case with water, any ice that formed would sink, and sease would freeze from the bottom up. Furthermore, the lowest layers would be insulated and would not all melt in summer. Thus over time, the seas would become a thin layer of liquid water at best, over solid ice. Life could not develop without liquid seas. In addition, ice is reflective, reducing the amount of sunlight absorbed, further reducing temperatures. Without ocean circulation, polar areas would be even colder, and there would be no rain.
Answer:
A. 1km
Explanation:
The 1 km is equal to 1000 m.
1. Increasing the pressure
In order to increase the solubility of gases in a liquid solvent, we must increase the pressure of the gas. This is the reason that the carbonation of soft drinks is carried out under pressurized conditions.
2. Supersaturated
When a solvent is "saturated", it is holding as much solute as it can at the given conditions. When additional solute is added by changing the conditions, the solvent contains more solute than normal so it is "supersaturated".
3. The concentration by weight may be calculated by dividing the weight of the solute by the weight of the solution. This is:
Weight of solute = 20 g
Weight of solution = 20 + 59 = 79 g
Wt % = (20/79) * 100 = 25.32%