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
Anna11 [10]
3 years ago
12

Squids and octopuses propel themselves by expelling water. They do this by keeping water in a cavity and then suddenly contracti

ng the cavity to force out the water through an opening. A 6.00 kg squid (including the water in the cavity) at rest suddenly sees a dangerous predator.If the squid has 1.85 kg of water in its cavity, at what speed must it expel this water to instantaneously achieve a speed of 2.70 m/s to escape the predator? Neglect any drag effects of the surrounding water.
Physics
1 answer:
liq [111]3 years ago
3 0

Answer:

The speed of water must be expelled at 6.06 m/s

Explanation:

Neglecting any drag effects of the surrounding water we can assume the linear momentum in this case is conserves, that is, the total initial momentum of the octopus and the water kept in it cavity should be equal to the total final linear momentum. That's known as conservation of momentum, mathematically expressed as:

p_f=p_i

with Pi the total initial momentum and Pf the final total momentum. The total momentum is the sum of the momentums of the individual objects, in our case the octopus and the mass of water that will be expelled:

p_{of}+p_{wf}=p_{oi}+p_{wi}

with Po the momentum of the octopus and Pw the momentum of expelled water. Linear momentum is defined as mass times velocity:

m_o*v_{of}+m_w*v_{wf}=m_o*v_{oi}+m_w*v_{wi}

Note that initially the octopus has the water in its cavity and both are at rest before it sees the predator so v_{oi}=v_{wi} = 0\frac{m}{s}:

m_o*v_{of}+m_w*v_{wf}=0

We should find the final velocity of water if the final velocity of the octopus is 2.70 m/s, solving for v_{wf}:

v_{wf}=-\frac{m_o*v_{of}}{m_w}=-\frac{(6.00-1.85)*(2.70)}{1.85}

v_{wf}=-6.06\frac{m}{s}

The minus sign indicates the velocity of the water is opposite the velocity of the octopus.

You might be interested in
A mass m = 3.9 kg hangs from a massless string wrapped around a uniform cylinder with mass Mp = 10.53 and radius R= 0.96 m. The
luda_lava [24]

Answer:

the rotational inertia of the cylinder = 4.85 kgm²

the mass moved 7.942 m/s

Explanation:

Formula for calculating Inertia can be expressed as:

I =\frac{1}{2}mR^2

For calculating the rotational inertia of the cylinder ; we have;

I = \frac{1}{2}m_pR^2

I = \frac{1}{2}*10.53*(0.96)^2

I=5.265*(0.96)^2

I=4.852224

I ≅ 4.85 kgm²

mg - T ma and RT = I ∝

T = \frac{Ia}{R^2}

a = \frac{g}{1+\frac{I}{mR^2}}

a = \frac{9.8}{1+\frac{4.85}{3.9*(0.96)^2}}

a = 4.1713 m/s²

Using the equation of motion

v^2 = u^2+2as \\ \\ v^2 = 2as \\ \\ v = \sqrt{2*a*s} \\ \\ v= \sqrt{2*4.1713*7.56} \\ \\ v = 7.942 \ m/s

3 0
3 years ago
Read 2 more answers
Find the cube roots of 27(cos 327° + i sin 327° ). Write the answer in trigonometric form.
Sati [7]

Answer:

z^{\frac{1}{3} }= -0.978 + i\cdot 2.836, z^{\frac{1}{3} }= -1.967 - i\cdot 2.265, z^{\frac{1}{3} }= 2.945 - i\cdot 0.571

Explanation:

The cube root of the complex number can determined by the following De Moivre's Formula:

z^{\frac{1}{n} } = r^{\frac{1}{n} }\cdot \left[\cos\left(\frac{x + 2\pi\cdot k}{n} \right) + i\cdot \sin\left(\frac{x+2\pi\cdot k}{n} \right)\right]

Where angles are measured in radians and k represents an integer between 0 and n - 1.

The magnitude of the complex number is 27 and the equivalent angular value is 1.817\pi. The set of cubic roots are, respectively:

k = 0

z^{\frac{1}{3} } = 3\cdot \left[\cos \left(\frac{1.817\pi}{3} \right)+i\cdot \sin\left(\frac{1.817\pi}{3} \right)]

z^{\frac{1}{3} }= -0.978 + i\cdot 2.836

k = 1

z^{\frac{1}{3} } = 3\cdot \left[\cos \left(\frac{3.817\pi}{3} \right)+i\cdot \sin\left(\frac{3.817\pi}{3} \right)]

z^{\frac{1}{3} }= -1.967 - i\cdot 2.265

k = 2

z^{\frac{1}{3} } = 3\cdot \left[\cos \left(\frac{5.817\pi}{3} \right)+i\cdot \sin\left(\frac{5.817\pi}{3} \right)]

z^{\frac{1}{3} }= 2.945 - i\cdot 0.571

5 0
3 years ago
Which is an example of projectile motion?
stiv31 [10]
A person throwing a rock
5 0
3 years ago
Read 2 more answers
Newton did not discover gravity, for early humans discovered that whenever they fell. what newton did discover is that gravity _
galben [10]

What Newton discovered is that  gravity extends throughout the universe.

<h3>What is gravity?</h3>

The term gravity refers to the force that acts on a body in the universe. It is gravity that makes an object to fall when it is thrown up. The force of gravity acts on every object in the universe and it extends through the universe.

Humans have always known about gravity when they fall from a height and when they threw things up. However, human did not know that gravity extends throughout the universe.

Thus, what Newton discovered is that  gravity extends throughout the universe.

Learn more about gravity:brainly.com/question/4014727

#SPJ1

6 0
1 year ago
You push a 15N cat in a box horizontally across the floor for 5m. What is the work done on the cat? W=Fx
scZoUnD [109]

Answer:

w=fx

w=(15)(5)

w=75

the angle between the deplacement and N is 0

3 0
2 years ago
Other questions:
  • What are different ways the soil is important to the water cycle?
    7·1 answer
  • Which of the following astronomical bodies or collection of astronomical bodies is likely to be a part of the others listed?
    6·2 answers
  • A 2200 kg car moving east at 10.3 m/s collides with a 3160 kg car moving east. The carsstick together and move east as a unit af
    6·1 answer
  • What effect does the Boat Velocity have on the waves seen by the observer?
    13·1 answer
  • A 10kg crate sits on a distant planet. The planet has the same mass as Earth, but 80% of the radius of Earth (Earth radius = 637
    6·1 answer
  • Three 5 Ohm resistors are connected in series to a 10 Volt power supply. What is the current through each resistor?​
    10·1 answer
  • A 3.63.kgkg chihuahua charges at a speed of 3.3m/s3.3m/s. What is the magnitude of the average force needed to bring the chihuah
    9·2 answers
  • How can I find the vertical velocity
    15·1 answer
  • A bowling ball moves 18 meters every 2 seconds down the lane at a bowling alley. What is the speed of the bowling ball?
    7·1 answer
  • Electromagnetic induction
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!