We take the derivative of Ohm's law with respect to time: V = IR
Using the product rule:
dV/dt = I(dR/dt) + R(dI/dt)
We are given that voltage is decreasing at 0.03 V/s, resistance is increasing at 0.04 ohm/s, resistance itself is 200 ohms, and current is 0.04 A. Substituting:
-0.03 V/s = (0.04 A)(0.04 ohm/s) + (200 ohms)(dI/dt)
dI/dt = -0.000158 = -1.58 x 10^-4 A/s
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
More info? I think the question is incomplete. Although, I believe the first 2 blanks are "rises"
Answer:
The second ball
Explanation:
Both balls are under the effect of gravity, accelerating with exactly the same value. The first ball is dropped, therefore its initial velocity is zero. Since the second ball has horizontal and vertical velocity components, its initial velocity is given by:
The vertical component is zero, however, it has a horizontal velocity, so its initial speed is not zero, therefore the secong ball has the greater speed at ground level.
B. Frequency remains unchanged because the energy in a photon is E=hf. So if the frequency changes so does the energy and that doesn't happen to EM waves entering a medium by the conservation of energy
