Need help on the first and second one

76.3°C

Considering the fact that;

Specific heat capacity of the hot chocolate = 3.751 kJ/kg C°

Specific heat capacity of milk is 3.93 kJ/(kg.C°)

But;

Heat gained by milk = Heat lost by hot chocolate

If the final temperature is x , then

Heat gained by milk

= 0.05 × 3.93 × (x-5)

= 0.1965x - 0.9825

Heat lost by hot chocolate;

= 0.2 × 3.751 × (95-x)

= 71.269 - 0.7502x

Therefore;

0.1965x - 0.9825 = 71.269 - 0.7502x

0.1965 x + 0.7502x = 71.269 + 0.9825

                  0.9467 x  = 72.2515

                               x = 76.319 °C

Approximately, the new temperature is 76.3°C

The maximum height of the rock above the surface is 202 m

1.1772 N

Given in the question,

mass of an object = 0.12 kg

To find the weight of this object we will use formula

weight = mass x acceleration due to gravity

We know that acceleration due to gravity on earth is constant = 9.81 m/s²

So,

weight = 0.12 x 9.81

           = 1.1772 N

Since it is not mention that were the object is so i assume that it is on earth but if it is on moon then acceleration due to gravity will be 1.625 m/s²

Use the equation q=mc/\T, where q is the heat lost, m is mass, and /\T is the change in temperature, and c is the specific heat.

q=50kg(3470J/kg K)(2K)

q=347000 J

Any other questions, just ask.

The heat lost from Nova's body is calculated using the specific heat formula Q = mcΔT. Substituting in the given values, we find that Nova's body lost 347,000 joules of heat.

The amount of heat lost by Nova's body can be calculated using the specific heat formula which is: Q = mcΔT, where 'Q' is the heat transferred, 'm' is the mass, 'c' is the specific heat, and 'ΔT' is the change in temperature. In this case, you would substitute the given values into this formula: Q = (50.0kg) * (3470J/kg°C) * (2.00°C)

When you multiply these together, the resulting heat loss is 347,000 joules. Therefore, Nova's body lost 347,000 joules of heat while she was skiing.

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Transformation of energy involves converting energy from one form to another, while transfer of energy involves the movement of energy from one system to another without a change in form.

The difference between transformation of energy and transfer of energy lies in the change of form and location of energy. Transformation of energy refers to the conversion of energy from one form to another, such as chemical energy being transformed into heat energy through metabolism. Transfer of energy, on the other hand, refers to the movement of energy from one system to another without a change in form, like the transfer of electrical energy to light energy in a light bulb.

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80.87 °C

Change in Temp of metal = (C of water *mass of water* Change in temp of water)/(C of metal*mass of metal)

That is;

Change of temp. of metal

   = [(4186 J/kg*°C)×(0.15kg)×(25°C-21°C)/[(899 j/kg*C)×(0.050kg)

     = 55.87 °C

The change in temp of the metal is -55.87 °C  as the metal cools down

Therefore;

Change in temperature = Final Temperature-Initial Temperature Initial                                       Temperature = Final Temp.-Change in Temp

                      =25 °C- (-55.87 °C)

                       = 80.87 °C

power ratings basically just compare with how many watts are used, like a tackle in football compares to a car engine

For historical reasons, the horsepower is occasionally used to describe the power delivered by a machine. One horsepower is equivalent to approximately 750 Watts. ... Thus, the power of a machine is the work/time ratio for that particular machine. A car engine is an example of a machine that is given a power rating.

Yes without an eletrical current attached there would be no electrons.

The wires are empty of charge when there is no current flowing and no electrons moving through wire.

The charge is the physical quantity which defines the object's electric field. The charged objects creates the electric field around it and attracts or repels another objects coming into that field.

The like charges repels each other and unlike charges attract each other.

When a wire is connected with battery or voltage source and switch is on, the electrons leave from positive terminal and heading towards the negative terminal. Thereby, resulting in flow of current through wire.

Charge q = no of electrons x charge on electrons

Thus, Yes, wires are ever empty of charge.

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meteorite is when a meteor survives the earth atmosphere and Impacts the earth successfully.

The little stone while it's still in space . . . "meteoroid" .

The streak of light it makes shooting through atmosphere . . . "meteor" .

The piece of it that's left when it gets to the ground . . . "meteorite" .

chemical energy into mechanical energy as well as heat.

Answer:

Explanation:

power station that burns coal

Non- renewable source of energy is exhaustible resources. The facility relies on a non-renewable source of energy is a power station that burns coal.

Renewable sorces:

Therefore, the facility relies on a non-renewable source of energy is a power station that burns coal.

Learn more about the non-renewable source,

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Answer:

It should be A.

Explanation:

Wire A and wire B are made from the same material and have the same length, however, wire A is wider which would allow more electricity or power to be transformed.

Unless im understanding your question wrong, but from what I do understand it is most likely A.

Hope this helps, could you mark me brainliest if it is right?

From the Earth, we can see multiple phases of the Moon in a 28 days cycle. These phases are not changes int he Moon or how much of it is lightened, but instead it is a result of the positions that the Earth, Moon, and Sun have in relation to each other. The Sun is always lighting one half of the Moon, which is the half that is turned toward it. From the Earth it doesn't seem that way, as we can see Moon that seems fully light, partially light on the left side, partially light on the right side, or totally dark, but all of that depends on how much of the lighted side of the Moon is turned toward the Earth.

Answer: Each consecutive disturbance has a further distance to travel before reaching observer A. For this reason, observer A observes a frequency of arrival that is less than the frequency at which the disturbances are produced.

Explanation:

The Doppler Effect

Suppose that there is a happy bug in the center of a circular water puddle. The bug is periodically shaking its  legs in order to produce disturbances that travel through the water. If these disturbances originate at a point, then they would travel outward from that point in all directions. Since each disturbance is traveling in the same medium, they would all travel in every direction at the same speed. The pattern produced by the bug's shaking would be a series of concentric circles as shown in the diagram at the right. These circles would reach the edges of the water puddle at the same frequency. An observer at point A (the left edge of the puddle) would observe the disturbances to strike the puddle's edge at the same frequency that would be observed by an observer at point B (at the right edge of the puddle). In fact, the frequency at which disturbances reach the edge of the puddle would be the same as the frequency at which the bug produces the disturbances. If the bug produces disturbances at a frequency of 2 per second, then each observer would observe them approaching at a frequency of 2 per second.

Now suppose that our bug is moving to the right across the puddle of water and producing disturbances at  the same frequency of 2 disturbances per second. Since the bug is moving towards the right, each consecutive disturbance originates from a position that is closer to observer B and farther from observer A. Subsequently, each consecutive disturbance has a shorter distance to travel before reaching observer B and thus takes less time to reach observer B. Thus, observer B observes that the frequency of arrival of the disturbances is higher than the frequency at which disturbances are produced. On the other hand, each consecutive disturbance has a further distance to travel before reaching observer A. For this reason, observer A observes a frequency of arrival that is less than the frequency at which the disturbances are produced. The net effect of the motion of the bug (the source of waves) is that the observer towards whom the bug is moving observes a frequency that is higher than 2 disturbances/second; and the observer away from whom the bug is moving observes a frequency that is less than 2 disturbances/second. This effect is known as the Doppler effect.

Answer:frequency increases

At the release point, the ball has kinetic energy,

[tex]\dfrac12m{v_0}^2[/tex]

and at its maximum height it has potential and kinetic energy,

[tex]-mgy+\dfrac12mv^2[/tex]

where [tex]y[/tex] is the maximum height attained above the release point.

The LoCoE tells us that we should have

[tex]\dfrac12m{v_0}^2=-mgy+\dfrac12 mv^2[/tex]

[tex]\implies v^2-{v_0}^2=-2gy[/tex]

[tex]\implies\left(7.20\dfrac{\rm m}{\rm s}\right)^2-\left(8.30\dfrac{\rm m}{\rm s}\right)^2=-2\left(9.80\dfrac{\rm m}{\mathrm s^2}\right)y[/tex]

[tex]\implies y=0.870\,\mathrm m[/tex]

Answer: The maximum height of the ball is 0.87 m

Explanation:

To calculate the height of the ball, we use third equation of motion:

[tex]v^2-u^2=2as[/tex]

where,

s = distance traveled  / height of the ball = ?

u = initial velocity of the ball = 8.30 m/s

v = final velocity of the ball = 7.20 m/s

a = acceleration due to gravity = [tex]-9.8m/s^2[/tex]  (negative sign represents the ball is going upwards that is against gravity)

Putting values in above equation, we get:

[tex](7.20)^2-(8.30)^2=2\times (-9.8)\times s\\\\s=\frac{(7.20)^2-(8.30)^2}{(2\times (-9.8))}=0.87m[/tex]

Hence, the maximum height of the ball is 0.87 m

Answer:

2. at the lowest point

Explanation:

The motion of the pendulum is a continuous conversion between kinetic energy (KE) and gravitational potential energy (GPE). This is because the mechanical energy of the pendulum, which is sum of KE and GPE, is constant:

E = KE + GPE = const.

Therefore, when KE is maximum, GPE is minimum, and viceversa.

So, the point of the motion where the KE is maximum is where the GPE is minimum: and since the GPE is directly proportional to the heigth of the bob:

[tex]GPE=mgh[/tex]

we see that GPE is minimum when the bob is at the lowest point,so the correct answer is

2. at the lowest point

Final answer:

The kinetic energy of a pendulum is maximum at the lowest point of its swing, where potential energy has been fully converted into kinetic energy.

Explanation:

The kinetic energy (KE) of a pendulum bob is at its maximum at the lowest point of its swing. This is because, as the pendulum falls from its highest point, it converts potential energy into kinetic energy. At the lowest point, all the potential energy that was present at the top has been transformed into kinetic energy, assuming no energy losses due to air resistance or friction. Conversely, at the highest points in the swing, the pendulum has maximum potential energy and minimum kinetic energy. Midway between the highest and lowest points, the pendulum has a mix of both kinetic and potential energy.

The list of choices you gave us doesn't have any true statements on it.

The statement  true of a concave lens  is Option A.

Concave lens is a type of spherical lens which is polished from outside and it reflects the light coming from the object through its inner surface.

This lens is diverging in nature which means that the light rays gets diverged after reflection.

The nature of the image formed by these lens is virtual and the size of the image will be less than the object and the image formed will be upright.

Hence, the correct option is A.

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It must have a medium to travel through.

Happy to help. Marking me the brainliest would really be appreciated.

Answer:

A. Distance over which the force is applied

Explanation:

As we know that in pulley system the mass of the car is balanced by the tension in the string

so here we will have

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

so here in order to decrease the force needed to lift the car we have to increase Distance over which the force is applied

So here if we increase the distance over which force is applied then it will reduce the effort applied by us in this pulley system as the torque will be more if the distance is more.

laser in the garage . . . D

wavelength of a sound . . . C

how sound travels . . . B

electromagnetic spectrum . . . D

Final answer:

The garage door safety mechanism functions by blocking a laser beam, which triggers the system to halt the door. The wavelength of sound informs us about pitch, with longer wavelengths corresponding to lower pitches. The speed of sound is dependent on the medium it travels through, and infrared light waves are not visible to the human eye.

Explanation:

The component that prevents a garage door from closing if there is an obstruction works as follows: The laser light travels in a straight line towards the receiver, and if an object blocks this path, the door will not close. The correct answer is D. An object in the path interrupts the beam, which signals the system to stop the door.

Regarding sound waves, the wavelength of a sound provides information about the pitch of the sound, which means C is the correct answer. A longer wavelength correlates with a lower pitch, and vice versa.

The speed of sound does not remain constant and varies depending on the material through which it travels, making B the correct statement. This variability is due to differences in density and elasticity of different media.

In the electromagnetic spectrum, D is the false statement because infrared light waves are not visible to the human eye. The electromagnetic spectrum includes a range of wavelengths, some visible and some not, such as infrared.

how does a pedometer help people reach their fitness goals?

a. It measures calories burned.  

b. It usually doubles as an MP3 player and keeps people motivated.  

c. They count steps during a workout.  

d. They measure the number of lifts done per exercise.

Answer:

By counting the steps it allows you to know the distance you have walked or ran.

Explanation:

A pedometer is an instrument that estimates the distance traveled by foot. It does this by recording the number of steps walked.

Some pedometers apps also have a feature that counts the calories burnt and lets you set the number of steps and calories you need to burn daily.

I hope this answer helps you.

Do Not Know but let me ask my Brother bc he did it last Year

Answer:

D Closer to moon than earth because earth has a greater mass than the moon

Explanation:

As we know that gravitational force is given by

[tex]F = \frac{Gm_1m_2}{r^2}[/tex]

so here if the net gravitational force at some distance between moon and earth is zero or equal due to moon and earth then in that case

[tex]F_{moon} = F_{earth}[/tex]

so here we can say

[tex]\frac{GM_m m}{r_1^2} = \frac{GM_e m}{r_2^2}[/tex]

so here we will have

[tex]\frac{M_m}{M_e} = \frac{r_1^2}{r_2^2}[/tex]

since mass of earth is more than mass of moon so we can say

[tex]\frac{r_1}{r_2} < 1[/tex]

so here we have

[tex]r_1 < r_2[/tex]

so the position is closer to moon because moon is of smaller mass than earth

Final answer:

In a spacecraft launched from Earth toward the moon, the spacecraft will be closer to the moon than to Earth when the gravitational forces acting on it are equal.

Explanation:

In a spacecraft launched from Earth toward the moon, the spacecraft will be closer to the moon than to Earth when the gravitational forces acting on it are equal.

The gravitational force between two objects depends on their masses and the distance between them. Although the moon has smaller mass compared to Earth, it is much closer to the spacecraft when it reaches that point where the gravitational forces are equal. This is because the spacecraft has traveled a greater distance away from Earth.

So, the correct answer is option B, closer to the moon because the moon has greater mass than the earth.

C. measure their amplitudes

C measures their amplitudes. Hope this helps! :)

The answer is modulation. In modulation a radio wave (also called the "carrier signal") is changed by the signal we want to send to the receiver, for example a song, or, in a wireless network, some data from a computer.

Answer:

Radio waves carry conversations, music, pictures, and information.

Explanation:

The normal force is always (underline, bold) is always perpendicular to the surface an object is sitting on. If the object is on an inclined plane, then the normal will not be vertical but it will be perpendicular to the angle of the incline.

The diagram below (left) shows a normal force (GH) that is not vertical, but it is perpendicular to the surface. The object on the right is the more usual normal a mass on a table top.

The vertical line on the right is the normal and it points up.

The correct option is A. perpendicular

In Physics, the normal force is the component of a contact force that is perpendicular to the surface that an object contacts. It is the support force exerted upon an object that is in contact with another stable object. Normal Force will be always acting opposite to the force falling on the surface. For example, if a book is resting upon a surface, then the surface is exerting an upward force upon the book in order to support the weight of the book.

Static electricity

hope this helps :)

the answer to this question is static electricity

Answer:

Hence, the correct option is (A) "If the mass of each object is very small".

Explanation:

The gravitational force between two objects is directly proportional to the product of masses and inversely proportional to the square of the distance between them.

The mathematical expression is given by :

[tex]F=G\dfrac{m_1m_2}{d^2}[/tex]

d is the distance between masses

Gravitational force is one of the fundamental force in the universe. If the masses of objects is too small, then their interaction with each other is hard to detect.

Hence, the correct option is (A) "If the mass of each object is very small".

The answer is C could be the moon, and D could be Venus. ;)

The answer is C could be the moon, and D could be Venus Good looks out there

The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.