The speed and velocity of a moving body become identical when it tends to move in a straight line.
The formula of the kinetic energy is KE = 0.5*m*v^2.
Given m = 80 kg and KE = 4000 J,
4000 = 0.5*80*v^2
v^2 = 100
v = 10 m/s
<span>#1
“A persons body continuing to move forward even though the car comes to
a sudden stop” Which newtons Law Do they pertain?
A: First Law </span>
<span>#2 “A fighter Pilot Feels Massive Amounts of forcé when his plane turns sharply” Which Newton Law?
A: First Law.
</span><span><span>You were following the
Newton's first law and kept your velocity straight until you departed from linear motion when you turn sharply; you are forced to follow the curve. <span>The
force that the jet exerts on you is called centripetal force and is
suitable for the center of curvature of the forced traveling path.</span></span>
</span><span>#3 “ A Paddle wheel boat pushed on water and the water pushes back causing the boat to move” Which Netwons Law?
C: Third Law</span>
Answer:
sound wave-electrical wave-radio wave
The characteristics of the scalar product allows to find the angle between the two vectors is:
The scalar product is the product between two vectors whose result is a scalar.
A . B = |A| |B| cos θ
Where A and B are the vectors, |A| and |B| are the modules of the vectors and θ at the angle between them.
The vector is given in Cartesian coordinates and the unit vectors in these coordinates are perpendicular.
i.i = j.j = 1
i.j = 0
A . B = (4 i - 4j). * -5 i + 7j)
A . B = - 4 5 - 4 7
A. B = -48
We look for the modulus of each vector.
|A| =
|A| =
|A| = 4 √2
|B| =
|B| = 8.60
We substitute.
-48 = 4√2 8.60 cos θ
-48 = 48.66 cos θ
θ = cos⁻¹
θ = 170º
In conclusion using the dot product we can find the angle between the two vectors is:
Learn more about the scalar product here: brainly.com/question/1550649