List two of the number of strategies you have learned
1 answer:
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If we pull an object vertically upwards then we need to apply a force which is equal in the magnitude of the weight of the object
now when we pull the same object upwards along an inclined plane with angle then we require a force which will balance the component of weight along the inclined
so it is given as
so as if we compare the two forces we can say that since the value of sine is always less than 1 for an angle less than 90 degree
so in the 2nd case when we pull the object along the inclined plane it will require less effort
so correct answer is
<em>A. reduce effort</em>
Answer:
The intensity of the sound in W/m² is 1 x 10⁻⁶ W/m².
Explanation:
Given;
intensity of the sound level, dB = 60 dB
The intensity of the sound in W/m² is calculated as;
where;
I₀ is threshold of hearing = 1 x 10⁻¹² W/m²
I is intensity of the sound in W/m²
Substitute the given values and for I;
Therefore, the intensity of the sound in W/m² is 1 x 10⁻⁶ W/m².
Answer: The weight of the air displaced by the balloon is less than the volume of the balloon.
Explanation:
A hot air balloon is a cloth wrap that contains several thousand cubic meters of air inside (a large volume of air). The burner heats the liquid propane to a gaseous state to generate a huge flame, which can reach more than 3 meters, thus heating the air mass inside the balloon. In this way,<u> its density is modified with respect to the air that surrounds it</u>, because the hot air is lighter than the outside air (less dense), causing the balloon to rise and float.
Now, if we know that the density of a body is directly proportional to its mass
and inversely proportional to its volume
:
We can deduce that <u>by increasing the volume of the body, its density will decrease.</u>
This is proof of <em><u>Archimedes' Principle</u></em>:
<em>A body totally or partially immersed in a fluid at rest, experiences a vertical upward thrust equal to the mass weight of the body volume that is displaced.</em>
In this case the fluid is the air outside. So, the warm air inside the balloon, being less dense, will weigh less than the outside air and therefore will receive an upward pushing force or thrust that will make the balloon ascend.