The intensity of a sound decreases by a factor of 4. As a result, the sound intensity level decreases by___.
A.4dB
B.6dB
C.8dB
d.16dB

Answer:

Option A is the correct answer.

Explanation:

 Static equilibrium means an object object is at rest and is in a state of equilibrium.

If we examine options B, C and D we can see that, in each case object is in a state of motion.

B) Tuna is in a motion.

C) Dolphin is a motion.

D) Zebra is a motion

In option A platypus lies motionless on the sand, which is an example of static equilibrium.

so, option A is the correct answer.

car suspension

guitar string

clips for hanging clothes

keyboards buttons

elevators

The five examples from daily life in which you see periodic motion caused by a spring or cord are car suspension, guitar string, clips for hanging clothes, keyboards buttons and elevators.

The motion which repeats itself after a fixed time period is called the periodic motion.

In daily life, every machine or simple machine we use is operated from a mechanism. The mechanism which involves the use of spring or cord for giving motion is elevator. The other examples are car suspension, guitar string, clips for hanging clothes and keyboards button.

Thus, the examples which shows periodic motion are listed above.

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Correct answer is Availability of soil minerals.

There are two types of limiting factors that affect plant population in a ecosystem. They are:

Biotic factors includes food, diseases etc. Such as Invasive weed species, seed dispersal by wind, disease-causing fungal spores are examples of biotic limiting factor.

Abiotic factors include sunlight, temperature and chemical environment. The availability of soil mineral is an example of abiotic limiting factor. Growth of plant population depends on availability of soil minerals.

In the context of an ecosystem, an abiotic limiting factor refers to non-living elements that may limit a plant's survival or growth. Among the options provided, 'Availability of soil minerals' serves as an abiotic limiting factor.

The question asks for an abiotic limiting factor, which refers to non-living aspects of an ecosystem that could limit a plant's growth or survival. In this case, the correct answer would be 'Availability of soil minerals.' Soil minerals are considered abiotic because they are non-living elements of the environment. They can limit plant growth if they are in short supply, as plants require specific minerals to carry out various biological functions. For example, nitrogen is a critical soil mineral that plants use to produce proteins and DNA.

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Special relativity can be used to study an object in which frame of reference ... C. A frame of reference that has a constant, positive acceleration.

The question is incomplete. The complete question is:

Special relativity cannot be used to study an object in which frame of reference?

A. A frame of reference that has no change in velocity

B. A frame of reference that is moving in a circle

C. A frame of reference that has a constant, positive acceleration

D. A frame of reference that has a constant, negative acceleration

Answer:

A frame of reference that has a constant, positive acceleration

A frame of reference that has a constant, negative acceleration

Explanation:

Special relativity applies to frames of reference in which an object is moving at constant velocity.

If the velocity is constant, it implies that acceleration will be zero hence options C and D will be correct since they both involve a non-zero change in velocity.

Answer: 24.24 m

Explanation:

A player throws football 50.0 m at 61° North of west. we will write this in terms of horizontal and vertical components.

Horizontal component: 50 cos 61° = 24.24 m which is westwards

Vertical component: 50 sin 61° = 43.73 m which towards North.

Refer to diagram below.

Thus, the westward component of displacement of the football is the horizontal component of the displacement = 24.24 m.

The westward displacement of the football that was thrown by a player 61.0° north of west can be calculated using trigonometry. Specifically, by multiplying the total displacement (50.0 m) with the cosine of the angle (61.0°), resulting in a westward displacement of approximately 25.5 m.

The student's question concerns the westward displacement of a football thrown by a player at a direction 61.0° north of west. This displacement is a component of the total displacement of the football. Since the direction is specified relative to west, the western component or the westward displacement can be calculated using basic trigonometry.

In this case, the westward displacement is the adjacent side of the triangle formed with the displacement as hypotenuse and the angle being 61.0°. Hence, the westward component can be calculated using cosine of the angle times the hypotenuse, which is 50.0 m. We can calculate it as follows:

Westward displacement = 50.0 m * cos(61.0°)

Using a calculator, this gives a westward displacement of approximately 25.5 m, after rounding to one decimal place. Thus, the football was displaced approximately 25.5 m to the west.

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According to Newton's principle two

F=m*a=>a=F/m=21/82=0.25 m/s²

Answer: Ultraviolet light should have a short wavelength, not a long wavelength.

Explanation:

Relation between the frequency and wavelength if given by:

[tex]\nu=\frac{c}{\lambda }[/tex]

[tex]\nu=\text{frequency of electromagnetic wave}[/tex]

[tex]\lambda =\text{wavelength of an electromagnetic wave}[/tex]

[tex]c=\text{speed of light}=3\times 10^{8} m/s[/tex]

From the above relation we can say that frequency and wavelength are inversely related to each other.

[tex]\nu\propto\frac{1}{\lambda }[/tex]

From the Gino's table, the mistake made by her was , instead of writing low wavelength for Ultraviolet rays she wrote long. Since the ultraviolet rays have higher frequency they have low value wavelength.

The maximum speed at which the car makes the turn without slipping is [tex]\boxed{54\,{{\text{m}} \mathord{\left/{\vphantom {{\text{m}} {\text{s}}}} \right.\kern-\nulldelimiterspace} {\text{s}}}}[/tex].

Further Explanation:

Given:

The coefficient of static fiction between the road and tyres is [tex]0.40[/tex].

The radius of curvature of the road is [tex]740\,{\text{m}}[/tex].

Concept:

As the car turn around the curved road, the centripetal force acting on the car should be balanced by the friction force acting on the car to avoid the slipping of the car on the road.

Write the force balancing equation for the forces acting on the car.

[tex]{F_{centripetal}} = {F_{frcition}}[/tex]      …… (I)

The centripetal force acting on the car is given by.

[tex]{F_{centripetal}} = \dfrac{{m{v^2}}}{r}[/tex]  

Here, [tex]m[/tex] is the mass of the car, [tex]v[/tex] is the velocity of the car and [tex]r[/tex] is the radius of the curvature of path.

The friction force acting on the car is given by.

[tex]{F_{fricton}} = \mu mg[/tex]  

Here, [tex]\mu[/tex] is the static friction coefficient and [tex]g[/tex] is the acceleration due to gravity.

Substitute [tex]\dfrac{{m{v^2}}}{r}[/tex] for [tex]{F_{centripetal}}[/tex] and [tex]\mu mg[/tex] for [tex]{F_{friction}}[/tex] in equation (I).

[tex]\begin{aligned}\frac{{m{v^2}}}{r} &= \mu mg\\ v&= \sqrt {\mu rg}\\\end{aligned}[/tex]  

Substitute the values in the above expression.

[tex]\begin{aligned}v&= \sqrt {0.40 \times 740 \times 9.8}\\ &= \sqrt {2900.8}\\ &= 53.85\,{{\text{m}} \mathord{\left/{\vphantom {{\text{m}} {\text{s}}}} \right.\kern-\nulldelimiterspace} {\text{s}}}\\&\approx 54\,{{\text{m}}\mathord{\left/{\vphantom {{\text{m}} {\text{s}}}} \right.\kern-\nulldelimiterspace} {\text{s}}}\\\end{aligned}[/tex]  

Thus, the maximum speed at which the car makes the turn without slipping is [tex]\boxed{54\,{{\text{m}} \mathord{\left/{\vphantom {{\text{m}} {\text{s}}}} \right.\kern-\nulldelimiterspace} {\text{s}}}}[/tex].

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Answer Details:

Grade: High School

Chapter: Circular motion

Subject: Physics

Keywords:  Curved section, circular, unbanked road, static friction, maximum safe driving, radius 740m, without slipping, centripetal force, friction force.

Answer:

On the basis of physical and chemical properties, pyrite can be differentiated from real gold.

Explanation:

Some properties which can be used to differentiate pyrite from real gold are given below:

i) Real gold is made of same kind of atoms while pyrite is made of combinations of atoms like Iron and Sulphur.

ii) Pyrite is lighter in color than real gold.

iii) When we heat pyrite and real gold, both show different colors at higher temperatures.  

iv) Pyrite is less dense and harder than real gold.

v) Real gold has weight 1.5 times than that of pyrite.

friction and gravity ....................

The motion of the cake batter from the bowl to the pan is influenced by gravitational force (noncontact), normal force (contact by the spatula), and adhesive force (contact with the bowl). These forces affect how the batter moves and is transferred into the pan.

When Lourdes mixes the cake batter and transfers it from the bowl to the pan, several forces are in play affecting its motion. These include:

Each force mentioned influences the flow and transfer of the cake batter, whether it is through contact, like the normal and adhesive forces, or from a distance, such as the gravitational force.

because the form can be watched over a long time for deviations from the mark.

like fingernails, the grow slowly too. after a time, they get clipped

Mark him brainliest! XD

(your welcome btw)

Final answer:

The total displacement of the person's daily walk, starting and ending at the same front porch, is zero, as displacement considers only the initial and final positions.

Explanation:

The question pertains to the concept of displacement in physics, which is different from distance. Displacement is a vector quantity that only considers the initial and final position of an object, ignoring the path taken. In the case of a person who walks one mile every day for exercise, starting from her front porch at 9:00 AM and returning to the same spot at 9:25 AM, her total displacement is zero. This is because her final position (the front porch) is the same as her initial position, meaning there has been no change in position regardless of the distance walked.

Answer:

D.

hope this helps

Answer:

10.0 kg

Explanation:

The problem can be solved by applying the law of conservation of momentum - the total momentum before the collision must be equal to the total momentum after the collision:

[tex]p_i = p_f\\m_A u_A + m_B u_B = m_A v_A + m_B v_B[/tex]

where:

[tex]m_A = 5.0 kg[/tex] is the mass of ball A

[tex]u_A = +20 m/s[/tex] is the velocity of ball A before the collision

[tex]m_B = ?[/tex] is the mass of ball B

[tex]u_B = +10 m/s[/tex] is the velocity of ball B before the collision (same sign of uA, since they are moving in same direction)

[tex]v_A = +10 m/s[/tex] is the velocity of ball A after collision

[tex]v_B = +15 m/s[/tex] is the velocity of ball B after collision

Re-arranging the equation, we can solve to find mB, the mass of ball B:

[tex]m_B u_B - m_B v_B = m_A v_A - m_A u_A\\m_B = \frac{m_A (v_A -u_A)}{u_B -v_B}=\frac{(5.0 kg)(10 m/s-20 m/s)}{10 m/s-15 m/s}=10.0 kg[/tex]

If N is the number of pizza’s the restraunt will make and the equation tells us that the restraunt will make 40 pizza’s, I believe this turns the equation into p=14(40).

Answer:

The  slices of pepperoni are 560.

Explanation:

The equation is given by

[tex]p=14 n[/tex]

We need to calculate the slices of pepperoni are needed to make 40 pizzas

Using given equation

[tex]p=14n[/tex]

Where, p = number of slices

n = number of pizza

Put the value of n in the equation

[tex]p = 14\times40[/tex]

[tex]p=560[/tex]

Hence, The  slices of pepperoni are 560.

When density increases the number of molecules stay the same, im not entirely sure but i hope its right.

If the power rating of the motor is 8x10^4 Watts and our equation for Power is:

[tex]Power=\frac{Energy}{time}=\frac{Work}{time}=\frac{Force \times Displacement}{time}\\\\P=Force \times Velocity[/tex]

Note that:

[tex]F=ma=mg[/tex]

where g is the average gravity on Earth which is approximately 9.8 m/s^2.

And so:

[tex]P=F \times V\\P=m \times g \times V\\\\\ m=\frac{P}{gv} \\\\[/tex]

[tex]m=\frac{8.1 \times 10^4 }{9.8 \times 3} =2755.1kg[/tex]

In terms of force:

[tex]F=mg=2755.1kg \times 9.8 \frac{m}{s^2}=27000N[/tex]

The maximum weight of motor that can lifted at the given speed is of 27000 N.

Given data:

The maximum power rating of the motor is, [tex]P = 8.1 \times 10^{4} \;\rm W[/tex].

The weight of elevator is, [tex]W = 1.8 \times 10^{4} \;\rm N[/tex].

The speed of motor is, v = 3.0 m/s.

Since, the power rating of motor is obtained due to the force experienced on the elevator. Then,

[tex]P = F \times v[/tex]

Solving as,

[tex]8.1 \times 10^{4} = F \times 3.0 \\F = 27000 \;\rm N[/tex]

Now, the force experienced on the elevator is due to the weight of motor. Then,

Force (F) = Weight of motor (W')

[tex]27000 = W' \\\\W' = 27000 \;\rm N[/tex]

Thus, we can conclude that the maximum weight of motor that can lifted at the given speed is of 27000 N.

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#1

As per work energy theorem work done by all forces must be equal to change in its kinetic energy

so correct answer will be

[tex]W_{net} [/tex] = change in kinetic energy

#2

Torque is defined as

[tex]\tau = r \times F[/tex]

[tex]\tau = rFsin\theta[/tex]

so here torque will be maximum when applied force is perpendicular to the rod

so first figure of rod is correct for maximum torque

#3

When car makes turn then its passengers moves outwards which is due to the property of inertia because due to this property passengers has tendency to move in same direction and hence it feels to move outwards

So correct answer will be

inertia

#4

As per energy conservation we can say

initial potential energy = final kinetic energy

[tex]PE = KE[/tex]

[tex]KE = mgH[/tex]

[tex]KE = 0.5(9.8)(0.5)[/tex]

[tex]KE = 2.5 J[/tex]

i think its b

hope this helps

Answer:The correct answer is option B.

Explanation:

Work done is defined product of force applied on an object and the displacement of an object on applying of force.It is measured in Joules.

[tex]W=Force\times Displacement[/tex]

1. Chet

Work done = [tex]50 N\times 1.0 m= 50.0 Joules[/tex]

2. Mika

Work done = [tex]40 N\times 2.0 m= 80.0 Joules[/tex]

3. Sara

Work done = [tex]30 N\times 1.5 m= 45.0 Joules[/tex]

4.Bill

Work done = [tex]60 N\times 0.5 m= 30.0 Joules[/tex]

The greatest work was done by Mika and least work was done by BIll. The order from the greatest amount of work done to the least.

Mika>Chet>Sara>Bill.

Hence ,the correct answer is option B.

Answer: She is incorrect to conclude that the reaction is endothermic.

As in the second trial, the temperature has increased by 20 °C , that means the heat has been released and energy is released in exothermic reactions.

Exothermic reactions: The reactions in which the energy of the products is less than the energy of the reactants, and the excess energy is released as heat.

Endothermic reactions: The reactions in which the energy of the products is more than the energy of the reactants, and the excess energy is absorbed as heat.

Explanation:

An endothermic reaction is a reaction in which the reactants absorb energy and the energy of products is more than that of reactants.

Whereas an exothermic reaction is a reaction in which the reactants have more energy as compared to products. Hence, there will be release of energy.

Therefore, when temperature is increased by [tex]20^{o}C[/tex] then it means we are providing more energy to the reactants. As a result, there will be release of energy. Hence, the reaction will be exothermic in nature and not endothermic.

Thus, we can conclude that the student is incorrect because the reaction is exothermic and not endothermic.

Work done to move the box is 100Joules.

The work done by any object is equal to the product of force applied and the distance moved by the object.

W =F.s

Given is the Force F =10N and distance moved s =10m

Then , the work done will be

W =10N x 10m

W =100J

Thus, the work done is 100J

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Given data

ball throws upwards at an angle 60°

Horizontal component (Vh) = 12.5 m/s,

Vertical component (Vv) = 21.7 m/s ,

The magnitude of throw/resultant velocity (V) = ?

The resultant velocity /the velocity with which ball is throws is determined by the following equation

                                   V = √[(Vh)² + (Vv)²]

                                       = √[(12.5)² + (21.7)²]

                                      = 25.04 m/s

                The resultant velocity or the velocity with which the ball is thrown is 25 m/s

Answer:

d

Explanation:

The acceleration stays the same. Velocity is the one that changes.

Answer:

C.As the two objects touch, thermal energy flows as heat from the warmer block to the colder block until particles in both blocks move at the same rate and reach the same temperature.

Explanation:

Heat is the transfer of thermal energy from an object at higher temperature to an object at colder temperature.

The temperature of an object is a measure of how fast the particles in the object move: the higher its temperature, the faster the particles move, the higher the average kinetic energy of the particles in the object. As a result, the particles of the object at higher temperature tend to transfer more energy (called thermal energy) to the particles of the object at colder temperature by colliding with them: this process continues until the particles of the colder object reach the same average kinetic energy as the particles of the warmer object, and this means that the two objects have reached the same temperature.

1.

Answer:

N = 77

Explanation:

1) As we know that Tension in the wire is given as

T = 2000 N

now mass per unit length of the wire is given as

[tex]\frac{m}{L} = \frac{20 \times 10^{-3} kg}{1.5 m}[/tex]

[tex]\frac{m}{L} = 0.013 kg/m[/tex]

Now fundamental frequency is given as

[tex]f_o = \frac{1}{2L}\sqrt{\frac{T}{m/L}}[/tex]

[tex]f_o = \frac{1}{2\times 1.5}\sqrt{\frac{2000}{0.013}}[/tex]

[tex]f_o = 129 Hz[/tex]

now highest frequency is given as 10000 Hz

so total harmonics is given as

[tex]N = \frac{10000}{129}[/tex]

[tex]N = 77 [/tex]

2.

Answer:

D) 7.14 Hz

Explanation:

As we know that

speed = (frequency)(wavelength)

given that

speed = 400 m/s

wavelength = 28 m

so frequency is given as

[tex]f = \frac{400}{28}[/tex]

[tex]f = 14.3 Hz[/tex]

now if wavelength is doubled then we will have

[tex]wavelength = 56 m[/tex]

new frequency will be

[tex]f = \frac{400}{56}[/tex]

[tex]f = 7.14 hz[/tex]

3.

Answer:

Number of nodes = 4

A) 4

Explanation:

Number of nodes = number of harmonics + 1

so here we know that

number of harmonics = 3

Number of nodes = 3 + 1

Number of nodes = 4

4.

Answer:

C) 35.1 Hz

Explanation:

fundamental frequency in an organ pipe closed at one end is given as

[tex]f = \frac{v}{4L}[/tex]

here we know that

v = 345 m/s

L = 2.46 m

now we have

[tex]f = \frac{345}{4(2.46)}[/tex]

[tex]f = 35.1 Hz[/tex]

5.

Answer:

A) 570

Explanation:

Number of harmonics is given as

[tex]N = \frac{maximum :\frequency}{fundamental\: frequency}[/tex]

[tex]N = \frac{20,000}{35.1}[/tex]

[tex]N = 570[/tex]

6.

Answer:

[tex]v = 37.12 m/s[/tex]

Explanation:

For fundamental frequency we know that

[tex]f_o = \frac{v}{2L}[/tex]

here we know that

[tex]f_o = 58 Hz[/tex]

[tex]L = 32 cm[/tex]

now we have

[tex]58 = \frac{v}{2(0.32)}[/tex]

[tex]v = 37.12 m/s[/tex]

Answer

standing waves are created when you have a rope attached to a point By moving your hand up and down we can create waves, and as we know that our rope is attached to a point on a wall, which means it has boundary. The waves will reflect back and interface with new waves and this is how standing waves are created.

hope this will help.

Answer:

Please see the explanation

Explanation:

As we know that standing waves have nodes and anti nodes which is produced by repeated interference of two waves of same frequency in opposite direction in the same medium. In this case when we have a rope attached to a point on a wall, we move the rope in up and down direction we will create waves.

The wave will go up to the wall and then reflect back and thus create an opposite wave. And as we can create a standing wave.

The atomic number is unique to each element and represents the number of protons in the nucleus of that atom. Therefore, it can be used to identify which element an atom belongs to.

The atomic number of an atom signifies the number of protons in the nucleus of that atom.

This number is unique to each element, making it a reliable identifier.

For example, Hydrogen has an atomic number of 1, which means it has 1 proton, while Helium has an atomic number of 2, indicating it has 2 protons.

No two elements share the same atomic number, hence, the atomic number can be used to identify an atom and determine which element it belongs to.

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Answer:

lights need elewctricity

Explanation:

She still needs to measure the distance between the slits.

To determine the correct option among all the options, we need to know about fringe width in young's double slits experiment.

(Wavelength × separation between screen and slits)/separation between the slits.

Thus, we can conclude that she needs the distance between the slits to determine the wavelength of light.

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