Answer:
V=22.4m/s;T=2.29s
Explanation:
We will use two formulas in order to solve this problem. To determine the velocity at the bottom we can use potential and kinetic energy to solve for the velocity and use the uniformly accelerated displacement formula:
Solving for velocity using equation 1:
Solving for time in equation 2:
It’s states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
Answer: <span>option B. Is liquid over a wide
temperature range; requires a large amount of energy per gram to raise
its temperature </span>
Justification:
Let's review every given statement:
A.
Is liquid over a narrow temperature range; requires a small amount of
energy per gram to raise its temperature
i) Water is liquid in a wide temperature range (depending of the pressure). At 1 atm the range is 0°C to 100 °C
ii) Water requires a large amount of energy per gram to raise its temperature. The amounf of energy required to increase the temperature of 1 gram of substance is called specific heat. Water has one of the largest specific heat which is a very important feature for the life. Since water can absorb large amounts of heat before changing its temperature, the temperatures of oceans keeps well and aquatic life is possible.
B. Is liquid over a wide
temperature range; requires a large amount of energy per gram to raise
its temperature
The two points were discussed in the choice A, concluding that they are true. So this is the right answer.
C. Has weak cohesive forces between molecules; is liquid
over a wide temperature range
i) Water has strong cohesive forces between molecules. The cohesive force is explained by the hydrogen bonds and manifested in the surface tension of water.
So, this option is wrong.
D. Has strong cohesive forces between
molecules; is liquid over a narrow temperature range.
The first statement is true as explained above, while the second one was denied during the discussion of choice A. So, this option is also false.
