(a) Differentiate the position vector to get the velocity vector:
<em>r</em><em>(t)</em> = (3.00 m/s) <em>t</em> <em>i</em> - (4.00 m/s²) <em>t</em>² <em>j</em> + (2.00 m) <em>k</em>
<em>v</em><em>(t)</em> = d<em>r</em>/d<em>t</em> = (3.00 m/s) <em>i</em> - (8.00 m/s²) <em>t</em> <em>j</em>
<em></em>
(b) The velocity at <em>t</em> = 2.00 s is
<em>v</em> (2.00 s) = (3.00 m/s) <em>i</em> - (16.0 m/s) <em>j</em>
<em></em>
(c) Compute the electron's position at <em>t</em> = 2.00 s:
<em>r</em> (2.00 s) = (6.00 m) <em>i</em> - (16.0 m) <em>j</em> + (2.00 m) <em>k</em>
The electron's distance from the origin at <em>t</em> = 2.00 is the magnitude of this vector:
||<em>r</em> (2.00 s)|| = √((6.00 m)² + (-16.0 m)² + (2.00 m)²) = 2 √74 m ≈ 17.2 m
(d) In the <em>x</em>-<em>y</em> plane, the velocity vector at <em>t</em> = 2.00 s makes an angle <em>θ</em> with the positive <em>x</em>-axis such that
tan(<em>θ</em>) = (-16.0 m/s) / (3.00 m/s) ==> <em>θ</em> ≈ -79.4º
or an angle of about 360º + <em>θ</em> ≈ 281º in the counter-clockwise direction.
Answer:
4.6×10^-7 m or 0.46nm
Explanation:
From
Wo= hc/λ
Where:
Wo= work function of the metal
h= planks constant
c= speed of light
λ= wavelength
λ= hc/Wo
λ= 6.6×10^-34 × 3×10^8/4.30×10^-19
λ= 4.6×10^-7 m
Answer:
d = 90 ft
Explanation:
Here in each swing the distance sweeps by the swing is half of the initial distance that it will move
So here we can say that total distance in whole motion is given as

since it is half of the distance that it will move in each swing so it would be a geometric progression with common ratio of 1/2
so sum of such GP is given by the formula



<em>Energy</em><em> </em><em>can</em><em> </em><em>neither </em><em>be</em><em> </em><em>created </em><em>nor</em><em> </em><em>be</em><em> </em><em>destroyed</em><em> </em><em>but</em><em> </em><em>can</em><em> </em><em>be</em><em> </em><em>converted</em><em> </em><em>from</em><em> </em><em>one</em><em> </em><em>form</em><em> </em><em>to</em><em> </em><em>another </em><em>.</em>
I don't know if you need to complete this question or do it otherwise, however, I managed to find on the Internet on several places this completion of your sentence:
<span>Electric current flows through a long rod generating thermal energy at a uniform volumetric rate of q = 2 x 10</span>⁶ W/m³.
I'm not sure whether that is the answer you were looking for, but that's what I found.