Why can't birds fly in space
2 answers:
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Answer:
Uk = 9.9 J
Explanation:
To calculate the kinetic energie (Uk), you can make use of this formula:
Uk = 0.5 * m * v²
given m = 55 kg and v = 0.6 m/s
Substituting in the formula gives:
Uk = 0.5 * 55 * (0.6)²
Uk = 0.5 * 55 * 0.36
Uk = 9.9 J
Extra:
Now let's examine the formula in relation to the SI units. <em>If you understand the following, it will give you great insight in how smart Phisics is inter twained by looking at formulas and their standard units. It will save you time in future to convert formulas, if you use the right standard units.</em>
The formula for kinetic energie is:
Uk = 0.5 * m * v²
Standard SI unit for mass m is kg.
Standard SI unit for speed v is m/s.
So v * v = v² and therefore v² must have the standard SI unit of m²/s².
From the formula, you see that the unit of Uk must be kg*m²/s² and since Uk is normally given in J, these both forms must be the same !
The main unit for Uk is the Joule. <em>Now</em><em> </em><em>please</em><em> </em><em>see</em><em> </em><em>the</em><em> </em><em>picture</em><em>,</em><em> </em><em>which</em><em> </em><em>shows</em><em> </em><em>the </em><em>relation</em><em> </em><em>between </em><em>the </em><em>J </em><em>and </em><em>other</em><em> SI units</em><em>.</em><em> </em><em>Please</em><em> </em><em>understand</em><em> </em><em>that</em><em> </em><em>you</em><em> </em><em>can</em><em> </em><em>construct</em><em> </em><em>your</em><em> </em><em>'own'</em><em> </em><em>formulas</em><em> </em><em>based</em><em> </em><em>these</em><em> </em><em>units</em><em>.</em><em> </em><em>Now</em><em> </em><em>here</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>time</em><em> </em><em>saver</em><em>:</em>
Because almost always the right units are <em>given</em> in a question, or because sometimes you can look up a constant in a table with an exotic and seemingly complicated unit, but that says a lot about the formula which must have been some how involved!
<em>By this, I hope you now understand the implication of using the right standard SI units and how that can help you figure out what formula is needed.</em>
Answer:
The magnitude of applied force,parallel to the incline is 575.38 N and parallel to the floor is 605 N.
Explanation:
Given:
Mass of the piano = 190 kg
Inclined angle = 18 degree
Considering gravity, = 9.8
And
Using, and
<em>FBD diagram is attached with all the force acting on the floor and and the inclined. </em>
We have to find the magnitude of forces,when the man pushes it parallel to the incline and to the floor.
a.
When the man pushes it parallel to the incline.
Balancing the forces as .
⇒
⇒
⇒ Here it is negative as the force is acting downward.
⇒ Plugging the values of mass and angle
.
⇒
⇒ N
b.
When the force is parallel to the floor.
⇒
⇒
⇒ Plugging the values.
⇒
⇒ N
So,
The magnitude of applied force in inclined direction is 575.38 Newton and parallel to the floor is 605 N.
