The velocity of the ferry relative to the current is 4.5 m/s.
<h3>Relative velocity</h3>
- Relative velocity is the velocity of a body as observed from the reference point of another body either stationary or in motion.
Since the river is flowing parallel to the shore and the ferry is moving perpendicular to the shore, their velocities are at right angles to each other.
The two velocities form a right angled-triangle of sides 2, 4 and a hypotenuse which gives the relative velocity of the ferry to the current.
Using Pythagoras rule:
- Let c be the hypotenuse
- a = velocity of the ferry, and
- b = the velocity of the current, and
c² = 4² + 2²
c² = 16 + 4
c = 20
c = √20
c = 4.47 m/s
c ≈ 4.5 m/s
Therefore, the velocity of the ferry relative to the current is 4.5 m/s.
Learn more about relative velocity and Pythagoras rule at: brainly.com/question/25617868
mass of the box = 20 kg
force of friction on the box due to surface



similarly kinetic friction on it



now the weight of the suspended block will be

so here the weight of the suspended block is less than the limiting friction on it
So here we will say that friction will counter balance the weight of the suspended block and it will not move at all
So acceleration of the box will be zero
<u>Answer</u>:
A force generated by an underwater earthquake applied to the waves of the ocean during a period changes the momentum of the wave, this is referred to as tsunami.
<u>Explanation</u>:
Most of the tsunamis are caused due to earthquakes and are the most destructive. When an earthquake of magnitude more than 7.5 in the Richter scale hits the ocean, there is a huge stir on the river and the balance of the water above it deteriorates. Waves are produced when water tries to get back its equilibrium.
This wave is formed due to the rise in water at the epicenter of the crisis and moves around the epicenter in the form of concentric circles. Remember that not all the earthquakes cause tsunamis, but in the same situation when the earthquake causes a movement in the seawater in the vertical direction. This movement arises on the ocean floor due to earthquakes, fractures or the sliding of plates.
The rope will remain taut until the particle makes 79⁰ angle.
<h3>Change in kinetic energy of the particle</h3>
The change in kinetic energy of the particle is calculated as follows;
ΔK.E = K.Ei - K.Ef
Before the particle will achieve the given angular displacement, it will touch two new corners. Total kinetic energy lost = 30%
ΔK.E = 100%K.E - 30%K.E = 70%K.E = 0.7K.E
- let the vertical displacement of the particle = h
- horizontal length = side of the prism = a
- hypotenuse side = length of the pendulum = L
<h3>Apply principle of conservation of energy</h3>
K.E = P.E
0.7K.E = mgh
0.7(¹/₂mv²) = mg(Lsinθ)
0.7(v²) = 2g(Lsinθ)
from third kinematic equation;
v² = u² + 2gh
v² = 0 + 2gh
v² = 2g(a tanθ)
0.7(2g(a tanθ)) = 2g(Lsinθ)
0.7(a tanθ) = Lsinθ
0.7a/L = sinθ/tanθ
0.7a/L = cosθ
(0.7 x 0.8)/(3) = cosθ
0.1867 = cosθ
θ = cos⁻¹(0.1867)
θ = 79⁰
Thus, the rope will remain taut until the particle makes 79⁰ angle.
Learn more about kinetic energy here: brainly.com/question/25959744
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Answer:
The answer is B
Explanation:
My answer to this quesstion is B because the black fur will absorb more light which then results for the black dog with black fur at a greater risk.