(a) The ball's height <em>y</em> at time <em>t</em> is given by
<em>y</em> = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve <em>y</em> = 0 for <em>t</em> :
0 = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
0 = <em>t</em> ((20 m/s) sin(40º) - 1/2 <em>g t</em> )
<em>t</em> = 0 or (20 m/s) sin(40º) - 1/2 <em>g t</em> = 0
The first time refers to where the ball is initially launched, so we omit that solution.
(20 m/s) sin(40º) = 1/2 <em>g t</em>
<em>t</em> = (40 m/s) sin(40º) / <em>g</em>
<em>t</em> ≈ 2.6 s
(b) At its maximum height, the ball has zero vertical velocity. In the vertical direction, the ball is in free fall and only subject to the downward acceleration <em>g</em>. So
0² - ((20 m/s) sin(40º))² = 2 (-<em>g</em>) <em>y</em>
where <em>y</em> in this equation refers to the maximum height of the ball. Solve for <em>y</em> :
<em>y</em> = ((20 m/s) sin(40º))² / (2<em>g</em>)
<em>y</em> ≈ 8.4 m
Explanation:
<em>Hello</em><em> </em><em>there</em><em>!</em><em>!</em><em>!</em>
<em>You</em><em> </em><em>just</em><em> </em><em>need</em><em> </em><em>to</em><em> </em><em>use</em><em> </em><em>simple</em><em> </em><em>formula</em><em> </em><em>for</em><em> </em><em>force</em><em> </em><em>and</em><em> </em><em>momentum</em><em>, </em>
<em>F</em><em>=</em><em> </em><em>m.a</em>
<em>and</em><em> </em><em>momentum</em><em> </em><em>(</em><em>p</em><em>)</em><em>=</em><em> </em><em>m.v</em>
<em>where</em><em> </em><em>m</em><em>=</em><em> </em><em>mass</em>
<em>v</em><em>=</em><em> </em><em>velocity</em><em>.</em>
<em>a</em><em>=</em><em> </em><em>acceleration</em><em> </em><em>.</em>
<em>And</em><em> </em><em>the</em><em> </em><em>solutions</em><em> </em><em>are</em><em> </em><em>in</em><em> </em><em>pictures</em><em>. </em>
<em><u>Hope</u></em><em><u> </u></em><em><u>it helps</u></em><em><u>.</u></em><em><u>.</u></em>
<span>Both electric and magnetic fields exert body forces, meaning they act from a distance. The like charges and poles in both repel; positive charge repels positive and the north pole repels the north pole. For both, the opposite poles/charges attract. Finally, only magnetic fields have poles, and there are two poles, namely the south and north, so they are dipolar.
The diagram that represents all of this information correctly is the third.</span>
Answer:
Diorite, Gabbro, and Granite
Explanation:
A light year is a measurement of distance that is used in the space. It is the distance that a light traveled for 1 year on Earth or 365 days on Earth at a speed of 3 x 10^8 meters per second. To convert the units from light year to the SI unit meters, we simply make use of the definition of the unit. We do as follows:
18.9 light years ( 365 days / 1 light year ) ( 24 h / 1 day ) ( 3600 s / 1h ) ( 3 x 10^8 m/s) = 1.79 x 10^17 meters
Therefore, 18.9 light years is equal to 1.79 x 10^17 meters.
