Which type of friction prevents a pile of rocks from falling apart?


Rolling friction

Kinetic friction

Cohesive friction

Static friction

Solution is given in following attachment.

The energy which is due to position is potential energy. So when the snow is lying on the mountain. It possess potential energy but when suddenly, it starts to move down the mountain, the potential energy is converted into the kinetic energy. Yet some force is exerting on the snow to stop the smooth flow of snow through mountains.

This example of frictional force may be due to presence of rough surface or stones. Generally, there are four types of friction as static, rolling, sliding and fluid friction. Though in this case when snow is lying it possess static friction, when flows then it possesses sliding and fluid friction both.

The answer is:

All the above

The explanation:

The volume and the temperature and the number of particles will affect the pressure of an enclosed gas.

because according to boyle's law when the temperature constant so the pressure and volume of a gas have an inverse relationship, when temperature is constant.

when:

PV = nRT

when p is the pressure

V is the volume

n is number of moles

T is temperature

from this law we can know that there is a relation  between P and V and when n has a relation with the number of particles so:

volume , temperature and number of particles affect the pressure of an enclosed gas.

Final answer:

The pressure of an enclosed gas can be affected by the volume of the container, the temperature of the gas, and the amount of gas within the container.

Explanation:

The pressure of an enclosed gas is affected by various factors including volume, temperature, and the amount of gas. When the volume of a gas container is decreased, there is less space for the gas molecules to move around, resulting in more frequent collisions with the container walls and an increase in pressure. This relationship is an example of Boyle's law. Conversely, increasing the volume will decrease the pressure. Additionally, raising the temperature of the gas increases the kinetic energy of the molecules, leading to more frequent and forceful collisions with the walls, thus increasing the pressure. Lastly, adding more gas molecules to the container, while keeping the volume and temperature constant, will also increase the pressure because there are more molecules to collide with the container walls per unit time.

A. anything less than 3.0 magnitude on a richters scale usually can't be felt by humans but instruments can pick it up.

Answer:

A. Less than 2.9

Explanation:

Richter scale is a measure of the intensity of the earthquakes designed and developed by Charles Richter in 1935. Its value ranges from 1.0 to 9.0 and greater. The earthquakes having a Richter magnitude of less than 2.9 are minor earthquakes which are slightly felt by a few humans but can be recorded on a seismograph. Earthquakes with magnitude above 2.9 can easily be felt by humans.

velocity is of sound id defined as distance covered by sound per unit time

here given that

distance covered by sound = 3.5 m

time taken by the sound = 0.919 millisecond

So the velocity of sound will be given as

[tex]v = \frac{d}{t}[/tex]

[tex]v = \frac{3.5}{0.919* 10^{-3}}[/tex]

[tex]v = 3808.5 m/s[/tex]

so the speed of sound in the given medium is 3808.5 m/s

As we know that speed of sound in any substance is given as

[tex]v = \sqrt{\frac{E}{\rho}}[/tex]

As per the data available online the speed of sound in gold is 3250 m/s while speed of sound in glass is 4500 m/s

So here we can say the above speed is in between these two mediums whose elasticity and density ratio is more than gold but less than glass.

So this velocity of sound is nearly match with the data obtained for copper

So this speed is approx obtained in copper

Blow dart is projected from a height of 1.2 m

Dart will hit the target at height 0.6 m

so the vertical displacement of the dart will be 1.2 - 0.6 = 0.6 m

here we can say that in vertical direction kinematics is applied

[tex]y = v_i* t + \frac{1}{2}at^2[/tex]

[tex]0.6 = 0 + \frac{1}{2}*9.8*t^2[/tex]

[tex]t = 0.35 s[/tex]

now we can say that dart will hit the target after t = 0.35 s

so in the same time it will cover the distance 12 m in horizontal direction

so here in order to find the initial speed we can say

[tex]d = v * t[/tex]

[tex]12 = v* 0.35[/tex]

[tex]v = \frac{12}{0.35}[/tex]

[tex]v = 34.3 m/s[/tex]

so dart is projected with speed 34.3 m/s in horizontal direction

The blow dart is launched with an initial velocity of around 34.3 m/s. This is determined by calculating the time of flight using the height difference and gravitational acceleration, then determining the velocity using that flight time and the horizontal distance to the target.

The subject of this question is physics, as it requires an understanding of kinematic equations for projectile motion to solve. First, let's figure out how long the dart is in the air. We're going to use the formula h = 0.5 * g * t^2, where h is the height difference (1.2m - 0.6m = 0.6m), and g is the acceleration due to gravity (approximately 9.81 m/s^2). Solving for t, we have sqrt((2*h) / g) = sqrt((2*0.6) / 9.81) = approximately 0.35 seconds.

Now that we know how long the dart was in the air, we can find out its initial horizontal velocity. Since horizontal motion is the constant velocity in the absence of air resistance, the initial velocity is simply the total horizontal distance divided by the time. Therefore, the initial velocity, v, is d / t = 12m / 0.35s = approximately 34.3 m/s. So the dart was launched with an initial velocity of roughly 34.3 m/s.

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here rocket starts from rest

It turns the booster and continue with constant acceleration

[tex]a = 4 m/s^2[/tex]

now in order to find the final velocity we can use kinematics equation

[tex]v_f = v_i + at[/tex]

here we know that

[tex]v_i = 0[/tex]

t = 3 s

now plug in all data in above equation

[tex]v_f = 0 + 4*3[/tex]

[tex]v_f = 12 m/s[/tex]

so the rocket will move rightwards with speed 12 m/s after 3 s of boosters

Answer:

55 miles per hour

Explanation:

Given

Distance d = 55 miles

t_o =1.00 pm

t_f = 2.00 pm

Solution

Duration of the trip

[tex]\Delta t = t_f - t_o\\\\\Delta t = 2.00 pm - 1.00 pm\\\\\Delta t = 1 hour[/tex]

Average velocity

[tex]v = \frac{d}{\Delta t} \\\\v = \frac{55}{1} \\\\v = 55 mph[/tex]

Friction in this case will act counter to the direction of the box's movement. The box moves left to right, so the force of friction acts in the opposite direction. (D)

Answer: Hello there!

first, we have two notions of the force of friction:

The force of friction is in the opposite direction of the motion direction.

It acts in the contact point between the objects.

Then if the box is moving from left to right, the friction force should point from right to left, and be in the bottom of the box (the contact point between the box and the floor).

The diagram that shows this is the D.

The answer is Newton's First law of motion.

Answer:

Newton's First law of motion.

Explanation:

Newton's First law of motion -

Newton' s first law of motion , also called the law of inertia .

According to this law , when an object is at rest or at stationary position , stays at that position and when the object is at motion , continues to be at the motion unless and until some force is acted on it .

Hence , the correct law for the given statement of the question , is Newton's First law of motion .

The correct answer is:

B. 2Na + Cl2 --> 2NaCl

In fact, this is the only reaction among the choices where the number of atoms of each element is conserved. In fact, we see that on the left we have 2 atoms of sodium and 2 atoms of chlorine, and on the right we have two molecules of NaCl, which means that we still have 2 atoms of sodium (Na) and 2 atoms of chlorine (Cl).

They grew up  to that sound. They love the sound of that same traffic sound.

Einstein's energy mass equivalence relation say that if the whole given mass is converted to energy then it would be

[tex]E = mc^2[/tex]

where

m = mass in kg

c = speed of light in m/s

this is the origination of quantum physics and by this formula we can relate the dual nature of light and particle

So correct relation above will be

[tex]E = mc^2[/tex]

the answer is B i just took it

Answer:

The object's final velocity is approximately \(17.15 \ m/s\) downward.

In order to calculate the voltage difference in the circuit, we need to look at the equation: V=IR.

In the equation:

V= Voltage

I= Current

R= Resistance.

Assuming we know this, We will plug it into an equation to find our voltage.

V=(.50a)x(24Ω)

If we solve for V, Your final answer will be: 12v (or 12 volts)

The voltage difference in a circuit that has the given resistance and current is 12 Volts.

Given the data in the question;

We know that; current is the ratio of potential difference and resistance.

It is expressed as:

[tex]I = \frac{V}{R}[/tex]

We substitute our given values into the equation and solve for the voltage

[tex]0.50A = \frac{V}{24ohms}\\\\V = 0.50A \ *\ 24ohms\\\\V = 12Volts[/tex]

Therefore,  the voltage difference in a circuit that has the given resistance and current is 12 Volts.

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Lol I just did this on USA Test Prep. The answer is D.

Option D - The liquid state is stabilized by the molecule's intermolecular forces resulting in a high enthalpy of vaporization → is the correct option.

We have enthalpy of vaporization.

We have to determine how is the enthalpy of vaporization related to intermolecular forces during a phase change.

Intramolecular forces are the forces that hold atoms together within a molecule.

According to the question -

The molecules inside liquid are held together by the intermolecular forces. A specific amount of heat energy is required to overcome these intermolecular forces in order to change the state from liquid to gas. This energy is called heat of vaporization. Hence, the intermolecular forces help liquid to stay in a steady state which will ultimately require more energy to separate the molecules.

Therefore, Option D is the correct Alternative.

To solve more questions on Intermolecular forces, visit the link below-

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Average speed is defined as the ratio of total distance covered in total given time

[tex]speed = \frac{distance}{time}[/tex]

here we know that total distance that man moved is

[tex]d_1 = 200 km[/tex]

[tex]d_2 = 100 km[/tex]

so total distance is

[tex]d = d_1 + d_2[/tex]

[tex]d = 200 km + 100 km[/tex]

[tex]d = 300 km[/tex]

now here total time of the motion is

[tex]t_1 = 6 hours[/tex]

[tex]t_2 = 4 hours[/tex]

total time will be given as

[tex]t = t_1 + t_2 [/tex]

[tex]t = 6 + 4 = 10 hours[/tex]

now by above formula

[tex]v_{avg} = \frac{300}{10}[/tex]

[tex]v_{avg} = 30 km/h[/tex]

so his average speed is 30 km/h

Can u tell me the answer choices? Than I will help.

Answer: Bernoulli’s

Explanation:

When a paper is crumpled and then released the air drag on the paper is less while when we put the flat paper and released it from rest we can see that there is large surface area due to which it will have more air drag and hence it will reach later

So we can say that air friction or air drag depends on the surface area of object

More will be the surface area more is the drag force of air and hence less is the effective acceleration due to gravity

So when we drop the two objects in vacuum it will not have any friction force

and hence they both will have same gravity downwards

So in that case the two objects will reach the ground in same time

so its answer will be

Both papers will reach the ground at the same time.

Answer:

the answer is they both hit at the same time

Explanation:

speed of the car at t = 10 s is given as 10 m/s

now at t = 30 s car comes to rest so v = 0

now in this velocity time graph we can say slope will show the acceleration of the car as we know that acceleration is rate of change in velocity

[tex]a = \frac{v_f - v_i}{\Delta t}[/tex]

as we know that

[tex]v_f = 0[/tex]

[tex]v_i = 10 m/s[/tex]

[tex]\Delta t = (30 - 10) = 20 s[/tex]

now from above formula

[tex]a = \frac{0 - 10}{20} = -0.5 m/s^2[/tex]

So slope of the graph will represent the acceleration of car which is 0.5 m/s^2

Actually the correct answer is going to be Linear, sloping downward.

Please mark Brainliest if this answer helped you.

These are all Examples of Models

The bunch of stuff in the jar is a mixture. The different kinds of pieces aren't bound to each other, and they can be easily separated.

The maximum magnitude of their resultant vector is when the two vectors are parallel and in the same direction, so they lie on the same axis. In this case, the magnitude of their resultant vector is simply the sum of the two magnitudes:

[tex]R=2.5 km+6.5 km=9.0 km[/tex]

The minimum magnitude of their resultant vector is when the two vectors are parallel but in opposite direction. In this case, the magnitude of their resultant vectors is just the difference between the two magnitudes:

[tex]R=6.5 km-2.5 km=4.0 km[/tex]

Transformer is used to change the voltage from higher value to lower value

It is done by changing the number of coils in primary and secondary coils

The working equation is given as

[tex]\frac{V_s}{V_p} = \frac{N_s}{N_p}[/tex]

here we have

[tex]V_s[/tex] = Secondary coil voltage = 120 V

[tex]V_p[/tex] = Primary coil voltage = 240,000 V

[tex]N_s[/tex] = Turns in secondary coil

[tex]N_p[/tex] = Turns in primary coil

Now by using the equation above

[tex]\frac{120}{240,000} = \frac{N_s}{N_p}[/tex]

now we have

[tex]\frac{N_p}{N_s} = \frac{240,000}{120}[/tex]

[tex]\frac{N_p}{N_s} = 2000[/tex]

so the ratio must be 2000

2000:1 is the ratio of the number of turns in the primary coil to the secondary coil of a transformer that steps down the voltage from 240,000 V to 120 V.

The ratio of the number of turns in the primary coil ([tex]n_p[/tex]) to the secondary coil ([tex]n_s[/tex]) of a transformer is directly related to the input ([tex]V_p[/tex]) and output voltage ([tex]V_s[/tex]).

The formula to calculate this ratio is:

[tex](V_p / V_s) = (n_p / n_s)[/tex]

Given:

Using the formula:

[tex](240,000 V / 120 V) = (n_p / n_s)[/tex]

This simplifies to:

[tex]2000 = (n_p / n_s)[/tex]

Therefore, the ratio of the number of turns in the primary coil to the secondary coil is 2000:1.

26 m/s - 20 m/s = 6 m/s

We know that either team is winning which means that the cumulative forces (sum of each girl force) on both teams are equal.

This means,

[tex]250 + 250 + 250 + 250 = 260 + 260 + 260 + x[/tex]

being x the force of the fourth girl on the east team.

Solving to x, you get

[tex]x = (250 + 250 + 250 + 250) - (260+260+260)

x = 1000 - 780

x = 220[/tex]

The fourth girl on the east is pulling with a force of 220N.

The force applied by fourth girl in east team is 220 N.

If neither side is wining, it means that force applied on both sides are equal.

Total force by team west = 250 N * 4 = 1000 N

Total force of 3 girls on east side = 260 N * 3 = 780 N

As we know the east team apply total force of 1000 N.

Force applied by the fourth girl in east team = 1000 N - 780 N = 220 N