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Answer:

The final angular velocity is rev/s is 0.293 rev/s.

Explanation:

Given;

mass of the merry-go-round, m₁ = 120 kg

radius of the merry-go-round, r = 1.8 m

initial angular velocity, ω = 0.4 rev/s

mass of the child, m₂ = 22 kg

Apply the principle of conservation angular momentum to determine the final angular velocity;

[tex]I_i= I_f\\\\\frac{1}{2} m_1r^2 \omega _i = \frac{1}{2} m_1r^2 \omega _f + m_2r^2 \omega _f\\\\ \frac{1}{2} m_1r^2 \omega _i =( \frac{1}{2} m_1r^2 + m_2r^2 )\omega _f\\\\\omega _f = \frac{ \frac{1}{2} m_1r^2 \omega _i}{\frac{1}{2} m_1r^2 + m_2r^2} \\\\\omega _f = \frac{ \frac{1}{2} m_1 \omega _i}{\frac{1}{2} m_1 + m_2}\\\\\omega _f = \frac{0.5 \ \times \ 120\ kg \ \times \ 0.4\ rev/s}{0.5 \ \times 120\ kg \ \ + \ \ 22 \ kg} \\\\\omega _f = 0.293 \ rev/s\\[/tex]

Therefore, the final angular velocity is rev/s is 0.293 rev/s.

Answer:

[tex]380697.33\ \text{N/m}[/tex]

[tex]0.138\ \text{m}[/tex]

Explanation:

m = Mass rocket = 1070 kg

v = Velocity of rocket = 3.75 m/s

a = Acceleration of rocket = 5g

g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]

The energy balance of the system is given by

[tex]\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2\\\Rightarrow kx=\dfrac{mv^2}{x}\\\Rightarrow kx=\dfrac{1070\times 3.75^2}{x}\\\Rightarrow kx=\dfrac{7250}{x}[/tex]

The force balance of the system is given by

[tex]ma=kx\\\Rightarrow m5g=\dfrac{7250}{x}\\\Rightarrow x=\dfrac{7250}{1070\times 5\times 9.81}\\\Rightarrow x=0.138\ \text{m}[/tex]

The distance the spring must be compressed is [tex]0.138\ \text{m}[/tex]

[tex]k=\dfrac{7250}{x^2}\\\Rightarrow k=\dfrac{7250}{0.138^2}\\\Rightarrow k=380697.33\ \text{N/m}[/tex]

The force constant of the spring is [tex]380697.33\ \text{N/m}[/tex].

Answer:

the energy when it reaches the ground is equal to the energy when the spring is compressed.

Explanation:

For this comparison let's use the conservation of energy theorem.

Starting point. Compressed spring

         Em₀ = K_e = ½ k x²

Final point. When the box hits the ground

         Em_f = K = ½ m v²

since friction is zero, energy is conserved

          Em₀ = Em_f

          1 / 2k x² = ½ m v²

          v = [tex]\sqrt{ \frac{k}{m} }[/tex]     x

Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.

Based on the law of conservation of energy, the elastic potential energy of the system when the spring is fully compressed is equal to the kinetic energy of the system at the moment immediately before the box hits the ground.

The energy in a compressed spring is elastic potential energy given by the formula:

where

The kinetic energy of a body is the energy the body the has due to it's motion.

Kinetic energy, KE, is givenby the formula below:

From the law of conservation of energy, the total energy in a closed system is conserved.

Based on this law, all the energy in the compressed spring is converted to the kinetic energy of the box just before it reaches the ground.

Therefore, the elastic potential energy of the system when the spring is fully compressed is equal to the kinetic energy of the system at the moment immediately before the box hits the ground.

Learn more about conservation of energy at: https://brainly.com/question/381281

Answer:

0.187 m

Explanation:

We'll begin by calculating the acceleration of the ball. This can be obtained as follow:

Mass (m) = 0.450 Kg

Force (F) = 38 N

Acceleration (a) =?

F = m × a

38 = 0.450 × a

Divide both side by 0.450

a = 38 / 0.450

a = 84.44 m/s²

Finally, we shall determine the distance. This can be obtained as follow:

Initial velocity (u) = 2.20 m/s.

Final velocity (v) = 6 m/s

Acceleration (a) = 84.44 m/s²

Distance (s) =?

v² = u² + 2as

6² = 2.2² + (2 × 84.44 × s)

36 = 4.4 + 168.88s

Collect like terms

36 – 4.84 = 168.88s

31.52 = 168.88s

Divide both side by 168.88

s = 31.52 / 168.88

s = 0.187 m

Thus, the distance is 0.187 m

2 bar magnets top to bottom with their long axes vertical, the top one with red S on top and blue N on bottom and the bottom magnet with red S on top and blue N on bottom. this diagram shows magnets that will attract each other. Hence option D is correct.

A permanent magnet is an item constructed of magnetised material that generates its own persistent magnetic field. A refrigerator magnet, for example, is commonly used to hold notes on a refrigerator door. Ferromagnetic (or ferrimagnetic) materials are those that can be magnetised and are strongly attracted to a magnet. These include the elements iron, nickel, and cobalt, as well as their alloys, some rare-earth metal alloys, and naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones that are strongly attracted to a magnet and are widely thought to be magnetic, all other substances respond weakly to a magnetic field via one of many different forms of magnetism.

Hence option D is correct.

To know more about magnet :

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Answer:

 m₂ = 4 kg

Explanation:

The moment of inertia is defined by

         I = ∫ r² dm

for bodies with high symmetry it is tabulated, for a spherical shell

        I = 2/3 m r²

in this case the first sphere has a radius of r₁ = 2m and a mass of m₁ = 1 kg, the second sphere has a radius r₂ = 1m.

They ask what is the masses of the second spherical shell so that the moment of inertia of the two is the same.

        I₁ = ⅔ m₁ r₁²

        I₂ = ⅔ m₂ r₂²

They ask that the two moments have been equal

        I₁ = I₂

        ⅔ m₁ r₁² = ⅔ m₂ r₂²

         m₂ = (r₁ / r₂) ² m₁

let's calculate

         m₂ = (2/1) ² 1

         m₂ = 4 kg

Answer:

Cell membrane helps to enclose the cell organelles and cytosol inside a cell. A cell wall is a ridgid, protective layer and it covers the cell membrane

Explanation:

Answer: 170km/hr to the South

Explanation:

The resultant velocity of the plane ilwill be gotten by adding the value of the velocities of the plane with the tallwind. It should be noted that the direction of the wind is.takwn into consideration.

Therefore, the resultant velocity of the plane will be:

= 20km/hr + 150km/hr

= 170km/hr to the South

Answer:

Resultant Velocity = 20 km/h + 150 km/h = 170 km/h

Explanation:

Answer:

The balloon will collapse

Explanation:

When air is removed from the bell jar, the balloon will collapse if the internal pressure from the balloon does not balance the atmospheric pressure from the surroundings.

If ' c ' is the speed of light, then the formula for it is . . .

c = 299,792,458 meters per second

Answer:

The correct answer is a

Explanation:

The speed of a sound wave depends on the square root of the modulus of compressibility and the density of the medium.

For the same medium, the speed of sound depends on the temperature of the fora

           v = [tex]v_o \ \sqrt{1 + \frac{T}{273} }[/tex]

Therefore, the different results that are obtained are due to changes in temperature. The correct answer is a

since this way it has the values ​​of the speed of sound for each temperature, for which it can compare with the results obtained from the trip.

For the  pendulum taken to the moon, The frequency change that would occur is mathematically given as

[tex]\frac{Fmoon}{Fearth}=0.408[/tex]

Generally, the equation for the Time period  is mathematically given as

[tex]T=2\pi\sqrt{L/g}[/tex]

Therefore

[tex]\frac{Fmoon}{Fearth}=\frac{\sqrt{g/6L}}{\sqrt{g/6L}}\\\\\frac{Fmoon}{Fearth}=\sqrt{1/6}[/tex]

[tex]\frac{Fmoon}{Fearth}=0.408[/tex]

In conclusion, The frequency change

[tex]\frac{Fmoon}{Fearth}=0.408[/tex]

Read more about frequency

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Answer:

.408

Explanation:

Answer:

Biodiversity decline continues due to a rapidly expanding human population. Habitat is damaged in order to meet growing needs for agriculture, urban development, water and materials. Fish, wildlife and plants are overharvested, despite mounting evidence that many harvesting practices are unsustainable.

Answer:

Explanation:

ice absorbs heat from the water. As the water molecules lose energy, they begin to slow down, and consequently to cool. So, it's kind of the opposite of what we might think: when we put ice in water, the ice doesn't give its cold to the water, it takes heat from the water.

Answer:

Hi how are you doing today Jasmine

Answer:

The answer is B

Explanation:

I did the USA test prep

Answer:

Explanation:

In equilibrium , weight of mug is equal to restoring force .

mg = kx where m is mass of mug , k is spring constant and x is extension .

k / m = g / x = 9.8 ms⁻² / .025 m

= 392

frequency of oscillation n = [tex]\frac{1}{2\pi}\sqrt{\frac{k}{m} }[/tex]

[tex]n=\frac{1}{2\pi}\sqrt{392 }[/tex]

= 4.46 per second.

Answer:

a)  

get mass of planet:  

ρ = M / V  

V = 4/3 * R_1^3  

M = ρ * V  

M = ρ * 4/3 * R_1^3  

equate force equations:

F = (GMm) / r^2     // r = R_2  

F = ma  

a = v^2/R_2  

F = m * (v^2/R_2)    

m * (v^2/R_2) = (GMm) / R_2^2  

plug in and solve v^2:  

m * (v^2/R_2) = (G * (ρ * 4/3 * R_1^3) *m) / R_2^2  

v^2 = (G * ρ * (4/3) * π * R_1^3) / R_2

put into kinetic energy equation:  

K = 1/2 * m * v^2  

K = 1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2

B)

givens:  

U = -(GmM) / R_2

plug in mass of planet:  

U = -(G * m * ρ * 4/3 * R_1^3) / R_2

C)

use previous equations and do some algebra:

K/U = (1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2) * -(R_2 / (G * m * ρ * 4/3 * R_1^3))  

K/U = -1/2

Answer:

T = 0.01 Nm

Explanation:

First, we will calculate the angular acceleration of the disk:

[tex]2\theta\alpha = \omega_f^2-\omega_i^2[/tex]

where,

θ = angular displacement = (6.37 rev)(2π rad/1 rev) = 40.02 rad/s

α = angular acceleration = ?

ωi = initial angular speed = 10 rad/s

ωf = final angular speed = 0 rad/s

Therefore,

[tex](2)(40.02\ rad/s)\alpha = (0\ rad/s)^2-(10\ rad/s)^2[/tex]

α = -1.25 rad/s²

negative sign shows deceleration

α = 1.25 rad/s²

Now, we will calculate the moment of inertia of disk:

[tex]I = \frac{1}{2}mr^2[/tex]

where,

I = Moment of Inertia = ?

m = mass of disk = 1 kg

r = radius of disk = 0.13 m

Therefore,

[tex]I = \frac{1}{2} (1\ kg)(0.13\ m)^2[/tex]

I = 0.00845 kg.m²

Now, the torque can be given as:

T = Iα

T = (0.00845 kg.m²)(1.25 rad/s²)

T = 0.01 Nm

Question (Fill-In-the Blank):

As wavelength decreases the frequency of a wave _______​

Answer:

Increases

Explanation:

When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same.

[tex] \boxed{ \boxed{ \huge\mathrm{Answer࿐}}}[/tex]

[tex] \mathrm{wavelength \: \: \dfrac{1}{ \propto} \: \: frequency }[/tex]

So, As wavelength decreases the frequency of a wave Increases.

_____________________________

[tex]\mathrm{ \#TeeNForeveR}[/tex]

Complete Question

A 10 kg medicine ball is thrown at a velocity of 15 km/hr ( m/s) to a 50 kg skater who is at rest on the ice. The skater catches the ball and subsequently slides with the ball across the  ice.

Calculate the kinetic energy after collision(in joules).

Answer:

 [tex]K.E=70.23J[/tex]

Explanation:

From the question we are told that:

Mass of ball [tex]m_b=10kg[/tex]

Speed [tex]V_{b1}=15 km/hr ( m/s)[/tex]

            [tex]V_{b1} = 4.1667 m/s[/tex]

            [tex]V_{b1} = 4.1667 m/s[/tex]

Mass of Skater [tex]m_s=50kg[/tex]

Generally the equation for conservation of momentum is mathematically given by

  [tex]m_sV_{s1}+m_bV_{b1}=(m_s+m_b)V[/tex]

  [tex]V=\frac{m_sV_{s1}+m_bV_{b1}}{(m_s+m_b)}[/tex]

  [tex]V=\frac {50+10*4.1667}{(50+10)}[/tex]

  [tex]V=1.53m/s[/tex]

Generally the equation for  Kinetic energy is mathematically given by

 [tex]K.E=\frac{1}{2}(m_s+m_b)V^2[/tex]

 [tex]K.E=\frac{1}{2}(50+10)(1.53)^2[/tex]

 [tex]K.E=70.23J[/tex]

Therefore kinetic energy K.E after collision is given as

 [tex]K.E=70.23J[/tex]

Answer:

Refraction

The rainbow is created because the index of refraction of water droplets changes as a function of wavelength. So, when the light enters the water droplet different colors will bend at different angles thus producing a dispersive effect known as a rainbow.

Answer:

D: Refraction

Explanation:

Refraction is the spitting of the electromagnetic spectrum, or the disembling of colours. For example, white is a mixture of all the colours.

Answer:

1 L = 1000 mL

125 mL = 125/1000 = 0.125 L

Answer:

0.125

Explanation:

divide by 1 000 to convert mL to liters

Answer:

https://www.slader.com/discussion/question/an-electron-is-accelerated-through-240-times-103-v-from-rest-and-then-enters-a-uniform-170-t-magnetic-field-what-are-a-the-maximum-and-b-the-9e425fbd/

( Here is solution)

Answer:

Option 2

Explanation:

Given

Two 2-Ohm resistors are in series  and these two resistors are in parallel with a 4-Ohm resistor

Equivalent resistance of two resistors in series = R1 + R2 = 2+2 = 4 Ohm

Equivalent resistance of two 4 Ohm resistors is parallel =1/ (1/4 +1/4) = 2 Ohm

Voltage = 12 Volts.

Hence, current = V/R = 12/2 = 6 Amp

Option 2 is correct

Answer:

The depth of the diver is 28.01 m

Explanation:

Given;

density of the seawater, ρ = 1,015 kg/m³

standard sea level pressure, P₀ = 1.0 atm = 101,325 Pa

the final reading of her pressure, P₁ = 3.75 atm = 379968.75 Pa

acceleration due to gravity, g = 9.8 m/s²

Let the depth she was diving at the final pressure = h

This depth is calculated as;

P₁ = P₀  +  ρgh

P₁ - P₀ =  ρgh

[tex]h = \frac{ P_1 \ - \ P_o}{\rho g} = \frac{379968.75 \ - \ 101325}{1015 \ \times \ 9.8} = 28.01 \ m[/tex]

Therefore, the depth of the diver is 28.01 m

Answer:

M v^2 / R = centripetal force

For Red: M v^2 / R = 5 * 9^2 / 1.5 = 270

For Blue M v^2 / R = 270 = 25 * 1.8^2 / Rb

So Rb = 25 * 1.8^2 / 270 = .3 m