(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.
m = mass of the truck = 23 00 kg
v = speed of the truck down the highway = 32 m/s
K = kinetic energy of the truck = ?
kinetic energy of the truck down the highway is given as
K = (0.5) m v²
inserting the values
K = (0.5) (2300) (32)²
K = (0.5) (2300) (1024)
K = (1150) (1024)
K = 1177600 J
hence the kinetic energy of the truck comes out to be 1177600 J
K = 1/2mv^2 of kinetic energy. The change in the object's kinetic energy is equal to the net work performed on it.
<h3>What causes the kinetic energy to change?</h3>
Equations. Mass and the square of the velocity are directly related to translational kinetic energy. The difference between the end and starting kinetic energies is known as change in kinetic energy.
<h3>In solar panels, is there kinetic energy?</h3>
employing semiconductor-cell-based panels. technique that uses solar thermal systems to store solar energy. This heat is used directly or transformed into concentrated solar power, or the sum of the potential energy and kinetic energy of an object or system, and electricity.
Learn more about kinetic energy here:
brainly.com/question/26472013
#SPJ4
Answer:
The time is 1.8s
Explanation:
The ball droped, will freely fall under gravity.
Hence we use free fall formula to calculate the time by the ball to hit the ground

Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.
From the question,
h=16m
Also, let take

By substitution we obtain,


Diving through by 9.8


square root both sides, we obtain


It is D,Copernicus.when he first proposed the idea everyone thought he was nuts and that it was not plausible.even though his theory wasn't so accurate it still helped further scientific research.HE was born February 19,1473 and he published a book about his theory.