1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
charle [14.2K]
3 years ago
10

The height of the tide measured at a seaside community varies according to the number of hours t after midnight. If the height h

, in feet, is currently given by the equation h=-1/2 t^2+6t-9, when will the tide first be at 6 ft?
Physics
1 answer:
antoniya [11.8K]3 years ago
6 0

Explanation:

Given that, the height of the tide measured at a seaside community varies according to the number of hours t after midnight. The height is given by the equation as :

h=-\dfrac{1}{2}t^2+6t-9

When the tide first be at 6 ft, put h = 6 ft in above equation as :

-\dfrac{1}{2}t^2+6t-9=6

-t^2+12t-18=0

On solving the above equation to find the value of t. It is equal to :

t = 3.551 seconds

or

t = 8.449 seconds

So, the tide of 6 ft is at  3.551 seconds and 8.449 seconds. Hence, this is the required solution.

You might be interested in
The emf induced in a coil that is rotating in a magnetic field will be at a maximum at which moment?
adelina 88 [10]
TLDR: It will reach a maximum when the angle between the area vector and the magnetic field vector are perpendicular to one another.

This is an example that requires you to investigate the properties that occur in electric generators; for example, hydroelectric dams produce electricity by forcing a coil to rotate in the presence of a magnetic field, generating a current.

To solve this, we need to understand the principles of electromotive forces and Lenz’ Law; changing the magnetic field conditions around anything with this potential causes an induced current in the wire that resists this change. This principle is known as Lenz’ Law, and can be described using equations that are specific to certain situations. For this, we need the two that are useful here:

e = -N•dI/dt; dI = ABcos(theta)

where “e” describes the electromotive force, “N” describes the number of loops in the coil, “dI” describes the change in magnetic flux, “dt” describes the change in time, “A” describes the area vector of the coil (this points perpendicular to the loops, intersecting it in open space), “B” describes the magnetic field vector, and theta describes the angle between the area and mag vectors.

Because the number of loops remains constant and the speed of the coils rotation isn’t up for us to decide, the only thing that can increase or decrease the emf is the change in magnetic flux, represented by ABcos(theta). The magnetic field and the size of the loop are also constant, so all we can control is the angle between the two. To generate the largest emf, we need cos(theta) to be as large as possible. To do this, we can search a graph of cos(theta) for the highest point. This occurs when theta equals 90 degrees, or a right angle. Therefore, the electromotive potential will reach a maximum when the angle between the area vector and the magnetic field vector are perpendicular to one another.

Hope this helps!
6 0
3 years ago
describe the time of day that an early explorer might have planned to enter a harbor and when he might have planned to leave
inessss [21]
He would try to enter as the tide is rising, and leave as the tide is falling. Those things happen at all different times of day during a month.
4 0
3 years ago
Please help me with these two questions
Andre45 [30]

Answer:

The kinetic energy would decrease because it has less mass

Explanation:

A battery

4 0
3 years ago
A 4.0 kg object will have a weight of approximately 14.8 N on Mars. What is the gravitational field strength on M
Pie

Answer:

Gravitational field strength =weight/mass

Explanation:

14.8N/4.0kg

3.7N/kg

3 0
2 years ago
Wave A has a high frequency and a short wavelength. Wave B has a lower frequency and a longer wavelength. Which wave carries gre
dusya [7]

Answer:

wave A

Explanation:

shortest wavelength carry the most energy

more energy in a wave, the higher its frequency. The lower the frequency is, the less energy in the wave.

4 0
2 years ago
Other questions:
  • The rate at which light energy is radiated from a source is measured in which of the following units?
    14·2 answers
  • A 2kg object travels to the right at 5.5 m/s after colliding with a 3kg object, initially at rest, what are the speeds of each o
    5·1 answer
  • What is an example of a system and describe the energy flow through it.
    9·1 answer
  • At 20°c, the resistance of a sample of nickel is 525 ohms. what is the resistance when the sample is heated to 70°C?​
    8·1 answer
  • 2. A carpenter tosses a shingle off a 9.4 m high roof, giving it an initial horizontal
    6·1 answer
  • As you move from left to right across the periodic table, what happens (in terms of metals/nonmetals, etc.)?
    7·2 answers
  • If a dart gun with a 20N/m spring inside of it is compressed a distance of 0.3m, How high into the air can it shoot a 0.15kg dar
    6·1 answer
  • Suppose a shrimp has been put on the ground that has just been taken out of water.Now touch the shrimp from a distance by a stic
    8·2 answers
  • Describe each of Newton’s Laws of Motion in ice skating. What can you design/develop to improve ice skating?
    6·2 answers
  • If every one-point change in the federal funds rate alters aggregate demand by $200 billion, how far did AD shift in response to
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!