Answer:
D
Explanation:
As you move down anything, towards the earth, (gravitational) potential energy decreases. This eliminates options B and C.
By the law of conservation of energy, the energy of the system stays the same. However the energy may be converted into different forms. In this case, the potential energy is converted into kinetic energy - this is what makes people move faster as they go down the slope. This makes option A wrong and option D right.
One-
The 6 is the only significant figure.
A . A person Jumping represents an unbalanced force.
<u>Explanation:</u>
If equal amount of force applied on any object from both the directions, then the object will not move and so the force is a balanced force.
If an unequal amount of force on an object from both sides then the object will move in the opposite direction of the maximum force applied, so it is called as an unbalanced force.
- When the force is unbalanced then its velocity will change, so options C and D are omitted.
- In Option B the vase is sitting on a table, just kept so there is no action of any unbalanced force.
- But a person jumping represents an unbalanced force, since the person do not jump with constant velocity and it will vary.
Answer:
- last option: none of<u> the above.</u>
Explanation:
Describing a solution as<em> concentrated</em> tells that the solution has a relative large concentration, but it is a qualitative description, not a quantitative one, so this does not tell really how concentrated the solution is. This is, the term concentrated is a kind of vague; it just lets you know that the solution is not very diluted, but, as said initially, that there is a relative large amount (concentration) of solute.
One conclusion, of course, is that <u>the solute is soluble</u>: else the solution were not concentrated.
On the other hand, the terms saturated and <em>supersaturated</em> to define a solution are specific.
A saturated solution has all the solute that certain amount of solvent can contain, at a given temperature. A <u>supersaturated solution has more solute dissolved than the saturated solution</u> at the same temperature; superstaturation is a very unstable condition.
From above, there is no way that you can conclude whether a solution is supersaturated or not from the statement that a solution is concentrated, so the answer is<u> none of the above</u>.
The approximate alcohol content is 210 ml.
Explanation:
It can be deduced from the question that each bottle is of 1000ml or 1 litre.
The first bottle is one half full means it has 500 ml of solution and it has 20% alcohol in it. So volume of alcohol in the solution is
20/100*500
=100 ml
The first bottle is one fifth full, so the volume of mixture is 1/5th of 1000ml
so it is 200ml having 30% alcohol
30/100*200
= 60 ml
The third bottle is one tenth full so its volume is 1/10*1000
100 ml. having 50% of alcohol
50/100*100
50 ml.
The alcohol content obtained from all these 3 litres is:
100+60+50
= 210 ml of alchohol is obtained from 800 ml of mixture.
