HELPPP


Which of the following statements about friction is FALSE .
1 ) Friction involves objects that are in physical contact .
2) Friction is less if surfaces are very smooth .
3 ) Friction is always in the direction of the motion .
4) Friction is caused by the uneven surfaces of touching objects

Answers

Answer 1
Friction is caused by the uneven surfaces of touching objects

Related Questions

Pls help need asap thank u!

Answers

Answer:

c

Explanation:

Which of the following statements about migration is true?

a. Migration is always from one region to another.
b. Animals always migrate within a region.
c. Migration always negatively impacts an ecosystem.
d. Animals migrate for various reasons.

Answers

Answer:

A and D

b and C are false

Answer:

D. Animals migrate for various reasons.

Explanation:

Got it right on Edge 2023. : )

HELP
A 3000-kg truck moving with a velocity of 10 m/s hits a 1000-kg parked car. The impact causes the 1000-kg car to be set in motion at 15 m/s . Assuming that momentum is conserved during the collision, determine the velocity of the truck immediately after the collision.

Answers

Answer:

Hey I go to GOC send me your number

Explanation:

Câu 20: Chọn câu sai:
A. Công là đại lượng vô hướng B. Công không có tính tương đối
C. Công phụ thuộc vào đường đi D. Công có giá trị đại số

Answers

Answer:

fr

Explanation:

How did ancient organisms become fossil fuels?

Answers

Answer:

One of the most widespread beliefs about fossil fuels — oil, natural gas and coal — is that these substances started out as dinosaurs. There’s even an oil company, Sinclair, that uses an Apatosaurus as its icon. That dino-source story is, however, a myth. What is true: These fuels got their start long, long ago — at a time when those “terrible lizards” still walked the Earth.

Fossil fuels store energy in the bonds between the atoms that make up their molecules. Burning the fuels breaks apart those bonds. This releases the energy that originally came from the sun. Green plants had locked up that solar energy within their leaves using photosynthesis, millions of years ago. Animals ate some of those plants, moving that energy up the food web. Others plants just died and decayed.

Any of these organisms, when they die, can be turned into fossil fuels, notes Azra Tutuncu. She’s a geoscientist and petroleum engineer at the Colorado School of Mines in Golden. But it takes the right conditions, including an oxygen-free (anoxic) environment. And time. A whole lot of time.

The coal we burn today got its start some 300 million years ago. Back then, dinosaurs roamed the Earth. But they didn’t get incorporated into coal. Instead, plants in bogs and swamps died. As this greenery sunk to the bottom of those wet areas, it partially decayed and turned into peat. Those wetlands dried out. Other materials then settled down and covered the peat. With heat, pressure and time, that peat transformed into coal. To extract coal, people now have to dig deeply into the earth.

Ancient living organisms are buried quickly and altered by intense heat and pressure to form fossil fuels. Fossil fuels include solid coal, liquid petroleum, and liquid natural gas.

Source; Goo_gle

if this was helpful then please mark me the brainliest

if i was not helpful then i am very sorry

How much time does it take for a school bus traveling at 15 m/s north to get a distance of 600 meters north?

Possible answers:
40 seconds
9,000 seconds
615 seconds
0.025 seconds

Answers

Answer:

40s

Explanation:

Please HELP!!!!!!!!!!!!!!!!!!!!!

Using Newton's First Law, explain why, in a frictionless environment, a car that is under motion will not stop moving?

Answers

Answer:

According to Newton's first law of motion, an object maintains its state unless a force acts on it. Therefore, a moving car does not change its direction and keeps its speed unless a force acts on it.

define potential difference as used in electricity​

Answers

Answer:

Explanation:

Testing answer please do not delete

the diffrence in potential betwen two points that represents the work involved or the energy relesed in the transfe of a unit quantity of electicity from one point to the other

You have a new goal of saving at least $4,500 over the course of the next year.

You already have $900 saved.

By how much would you need to increase your monthly net savings in order to meet this goal?

Answers

Answer:

You would need to save $300 every month to meet your savings goal.

Explanation:

4,500-900=3,600

3,600/12=300

Answer:

answer is 200

Explanation:

edge 2021

A flea can jump with an initial velocity of 2.2 m/s at an angle of 21° with respect to the
horizontal.

Answers

Answer:

Explanation:

If no one can see it because the lights were out. Did the flea really jump?

What do you want here?

Max height (2.2sin21)²/ 2(9.8) = 3.2 cm

Time of flight 2(2.2sin21)/ (9.8) = 0.16 s

distance of flight (2.2cos21)(0.16) = 33 cm

1. As the angle of the ramp is increased, the normal force increases /decreases / remains the same and the friction-force increases /decreases / remains the same. [1 Point] 2. As the angle of the ramp is increased, the force parallel increases /decreases / remains the same. [1 Point] 3. The angle at which the force down the plane was equal to the force of friction (for the cabinet) was _____________. [1 Point] 4. Consider a very low (~ zero) friction, 5.0 kg skateboard on a ramp at an angle of 15o to the horizontal. What would be the net force that would cause acceleration when the skateboard is allowed to move

Answers

(1) As the angle of the ramp is increased, the normal force decreases.

(2) As the angle of the ramp is increased, the parallel force increases.

(3) The angle at which the force down the plane was equal to the force of friction is zero degree.

(4) The net force that would cause acceleration is 47.33 N.

Let the angle of inclination of the ramp = θ

(1)

The normal force on an object on the ramp inclined to the ramp is calculated as follows;

[tex]F_n = mgcos (\theta)[/tex]

when θ is 0;

[tex]F_n = mgcos (0)\\\\F_n = mg[/tex]

when θ is 90;

[tex]F_n = mgcos(90)\\\\F_n = 0[/tex]

Thus, as the angle of the ramp is increased, the normal force decreases.

(2)

The parallel force on an object on the ramp inclined to the ramp is calculated as follows;

[tex]F_x = mgsin(\theta)\\\\[/tex]

when θ is 0;

[tex]F_x = mgsin(\theta)\\\\F_x = mgsin(0) \\\\F_x = 0[/tex]

when θ is 90;

[tex]F_x = mgsin(90)\\\\F_x = mg[/tex]

Thus, as the angle of the ramp is increased, the parallel force increases.

(3)

The force of friction is calculated as follows;

[tex]F_n = \mu F_n[/tex]

[tex]F_k = \mu mgcos(\theta)[/tex]

[tex]F_k = \mu mg cos(0)\\\\F_k = \mu mg[/tex]

Thus, the angle is zero degree

(4)

The net force that would cause acceleration is calculated as follows;

[tex]F_k = Fn\\\\F_k = mg cos(\theta)\\\\F_k = 5 \times 9.8 \times cos(15)\\\\F_k = 47.33 \ N[/tex]

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a father pulls his young daughter on a sled (where the combined mass of his daughter and the sled are 40 kg) with a constant velocity up a snowy hill that is inclined at 14 to the horizontal. a) if the coefficient of kinetic friction between the sled's runners and the snow is 0.15, what is the tension force of the rope on which the father pulls

Answers

Answer:

Explanation:

We are not told what angle the pull rope is to any other reference. That could make a huge difference in the result.

If we ASSUME that the rope pulls parallel to the slope

Then , if T is rope tension

                                  F = ma

T - mgsinθ - μmgcosθ = m(0)

                                 T = mg(sinθ + μcosθ)

                                 T = 40(9.8)(sin14 + 0.15cos14)

                                 T = 151.88677... 150 N

If the rope pulls the sled at a positive angle relative to the slope, As one might expect from an adult holding the rope, then the tension will be increased because only the Tension portion parallel to the slope causes motion in that direction, but will be decreased because the Normal force, and therefore the friction force, of the slope on the sled will be decreased.

name a substance which will undergo change E​

Answers

Answer:

Water

Explanation:

At 0 degrees it's solid...Then it melts into a liquid and at 100 degrees it's gas Simple

real answers only pls

Answers

Answer:

1. it spins

2. falls in a curve

3. falls flat on the floor

Energy Transfer and Temperature Quick Check 1 of 41 of 4 Items Question Use the table to answer the question. Sample Observation 1 The drop of food coloring spreads slowly. 2 The drop of food coloring spreads very quickly. A student places a drop of food coloring into two water samples. Her observations are shown in the table. Which statement best explains the observations in the table? (1 point) The water molecules of sample 1 are moving faster. The water molecules of sample 1 are moving faster. The temperature of sample 2 is close to freezing. The temperature of sample 2 is close to freezing. The temperature of sample 2 is higher. The temperature of sample 2 is higher. The water molecules of sample 1 are transferring more kinetic energy. The water molecules of sample 1 are transferring more kinetic energy.

Answers

Answer: Measure the initial temperature of the water using the thermometer Poke through a food substance measuring 0.5 grams using the needle with the handle. Turn on fire on the burner. Set the food substance on the needle to fire on the burner. Once the food substance starts to burn, place it under the test tube so the water inside it can absorb heat.

Explanation:

Hope this helps!

Which term describes energy stored in the bonds between atoms?
A. Nuclear energy
B. Chemical energy
O C. Thermal energy
D. Sound energy

Answers

Answer:

B. Chemical energy

Explanation:

chemical energy is the energy stored in the bonds between atoms

Please show your workmkmmkekdmnesnndndndndn

Answers

Answer:

Explanation:

Remark

The question really is how long does the projectile stay in the air if it was just dropped from a height of 46 meters.

Givens

vi = 0

a = 9.81 m/s^2

h = 46 m

t = ?

Solution

d = vi*t + 1/2 a t^2

46 = 0 + 1/2 * 9.81 * t^2       multiply both sides by 2

92 = 9.81 * t^2                     divide by 9.81

t^2 = 9.38                            Take the square root of both sides

sqrt(t^2) = sqrt(9.38)

t = 3.06 seconds.

In 3.06 seconds the object will hit the ground, thus stopping it. How far horizontally does it go in that time.

d = r * t

d=?

r = 102 m/s

t = 3.06 seconds

d = 102 * 3.06

d = 312.4  meters.

1) A bowling has a mass of 5 kg and a speed of 8 m/s. What is its momentum?
2) If the bowling ball started from a momentum of O and reached a momentum of 40
kg*m/s in 2 seconds. What is the impulse impacted on the bowling ball?
3) What is the force of impact for the 2 seconds?

Answers

Hgihucycyvyvuvuvuvuvuvuvuvvuvuvuv

what is 4 differences between saturated unsaturated and supersaturated solutions

Answers

Answer:

Unsaturated Solution: Less amount of salt in water, clear solution, no precipitation. Saturated Solution: The maximum amount of salt is dissolved in water, Colour of the solution slightly changes, but no precipitation. Supersaturated Solution: More salt is dissolved in water, Cloudy solution, precipitation is visible.

An instructor gives a demonstration in which he makes a standing wave on a long thin slinky. The slinky is 6.0 meters long. If you see 3 loops on the slinky when the instructor shakes the end of the slinky at a rate of 2.50 cycles per second, then the speed (in m/s) of transverse traveling waves on the slinky is

Answers

The characteristics of standing waves allows to find the result for the speed of the wave is:

The speed wave is:  v = 10 m / s

The wave is a way of transmitting energy without mass displacement, , in the attachment we can see a diagram of the standing wave.

Each cycle corresponds to half a wavelength,  they indicate that the frequency is 2.50 Hz and there are three cycles, so the wavelength is:

      L = [tex]n \frac{\lambda}{2}[/tex]

      λ = 2L/n

      λ = 2 6 /3

       λ = 4 m

Wave speed is related to wavelength and frequency

        v = λ f

         v = 4 2.5

         v = 10 m / s

In conclusion, using the characteristics of standing waves we can find the result for the speed of the wave is:

The wave speed is:   v = 10 m / s

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Which graph uses bars to show data that are broken into intervals?
O A. Scatter plot
O B. Bar graph
O C. Box-and-whisker plot
O D. Histogram

Answers

Answer:

A. scatter plot?

Explanation:

I dont really know if I'm right... sorry.

A 500-kg golf cart is moving on level ground in a circular path of radius 10 m with a speed of 12 m/s. What is the centripetal force acting on the cart?

Answers

Answer:

7200N

Explanation:

Centripetal force is directly proportional to the product of the mass and the square of the velocity and inversely proportional to the radius given.

A 3000 kg car stops at a red light, and is rear-ended by a 5000 kg truck traveling at 20m/s. In the collision, the two cars stick together. What is the final speed of the two cars just after the collision in m/s (Numeric Answers only)​

Answers

Explanation:

this is actually not as simple as it sounds here.

quite some energy is lost in the deformation of the bodies of car and truck, and it also needs more energy to get a standing object going than to accelerate an already moving object.

but assuming the simple described circumstances, then the energy and impulse of the moving truck of 5000 kg is transferred to a new combined system of car and truck of now 5000 + 3000 = 8000 kg.

so, the 20m/s inertia energy of the truck is now distributed to the truck/car combination.

since the same energy has to move now more mass, it is clear that the combined speed will be lower.

20×5000 = x×8000

20×5 = x×8

x = 100/8 = 12.5 m/s

that is the resulting speed of the combined truck/car object.

A person is driving a car in a roundabout at 20 m/s so that its centripetal acceleration is 5 m/s2 . How much time it takes to complete 1 circle around the roundabout?

Answers

Answer:

Ac = v²/r

where, Ac is centripetal acceleration

v is velocity

r is radius

5 = (20)²/r

r = 400/5

r = 80m

from,

w = 2πf

where, w = angular velocity and f frequency

w = v/r

f = n/T

then,

v = 2πrn ,n = 1 to complete 1 cycle

T

T = 2πr/v

T = 2π*80/20

T = 25.14seconds.

The car would take 25.14s to complete 1 cycle of the roundabout.

An object of mass 1.0 kg is at rest on a smooth inclined plane with height h, length 8 m,
and which makes an angle of 30° with the horizontal. The object is allowed to move, it
slides down and onto a rough horizontal surface. After traveling a distance of 4 m it hits a spring and travels 1.3 m more, all along the rough horizontal surface. The spring
constant is 26.5 N/m. What is the coefficient of kinetic friction for the horizontal surface?

Answers

The coefficient of kinetic friction for the rough horizontal surface is 0.66.

The given parameters;

mass of the object, m = 1 kglength of the inclined plane, L = 8 mangle of inclination of the plane, θ = 30⁰ distance traveled before hitting the spring, d₁ = 4 mdistance traveled after hitting the spring, d₂ = 1.3 mthe spring constant, k = 26.5 N/m

Apply work-energy theorem; the work done the force of friction is equal to the energy stored in the spring.

[tex]F_kd_1 = \frac{1}{2} kd_2^2\\\\\mu_kmg cos(\theta)d_1 = \frac{1}{2} kd_2^2\\\\\mu_k(1 \times 9.8 \times cos(30)\times 4) = \frac{1}{2} \times 26.5 \times (1.3)^2\\\\33.95\mu_k = 22.39\\\\\mu_k = \frac{22.39}{33.95} \\\\\mu_k = 0.66[/tex]

Thus, the coefficient of kinetic friction for the rough horizontal surface is 0.66.

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The volume of an ideal gas is increased from 0.6 m3 to 2.4 m3 while maintaining a constant pressure of 1000 Pa (1000 N/m2). Determine, in J, the amount of work done by the gas in this expansion.

Answers

The amount of work done by the gas in the given expansion is 1800 J.

The given parameters;

initial volume of the ideal gas, V₁ = 0.6 m³final volume of the ideal gas, V₂ = 2.4 m³constant pressure of the gas, P = 1000 Pa

The amount of work done by the gas in the given expansion is calculated as follows;

W = PΔV

where;

ΔV is the change in volume of the gas

Substitute the given parameters and solve for the work done;

W = 1000(2.4  -  0.6

W = 1800 J

Thus, the amount of work done by the gas in the given expansion is 1800 J.

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in a collision, a 25.0kg mass moving at 3.0m/s transfers all of its momentum to a 5.0kg mass. What is the velocity of the 5.0kg mass after the collision?

Answers

Answer:

Explanation:

The 25.0 kg mass has momentum before the collision of

p = 25.0(3.0) = 75 kg•m/s

If all this momentum gets transferred into a 5.0 kg mass, the velocity of the 25.0 kg mass will be zero and the velocity of the 5.0 kg mass will be

75 / 5.0 = 15.0 m/s

Getting this to occur will require an addition of a significant amount of energy via an internal explosion or release of spring potential energy. This can be shown by looking at kinetic energies.  

Initial system kinetic energy is ½(25.0)3.0² = 112.5 Joules

After the collision, system kinetic energy is ½(5.0)25² = 1,562.5 Joules

so 1562.5 - 112.5 = 1450 Joules of energy must be released during the collision to complete this scenario.

The most efficient energy transfer without energy release is an ideal elastic collision. Had these two masses been in such a collision with the given initial conditions, the 5 kg mass would have moved away at 5.0 m/s taking with it 5(5) = 25 kg•m/s of momentum leaving the 25 kg mass with 75 - 25 = 50 kg•m/s of momentum and a velocity of 50/25 = 2.0 m/s. Both masses are now traveling in the same direction as the original velocity, but at different speeds. Notice kinetic energy is conserved in elastic collisions

½(25)2² + ½(5.0)5² = 112.5 Joules.

The only time one mass can transfer its entire momentum to another mass without additional energy addition or subtraction is when the two colliding masses are identical in magnitude. Think pool balls colliding on a table.

When converted to a household measurement, 9 kilograms is approximately equal to a

Answers

Answer:

D) 19.8 lbs

Explanation:

1kg in household measurement is equal to 35.274 ounces. 35.274*9=317.466 ounces.

1kg is also equal to 2.205 lbs. 9*2.205=19.8416

9 kg is also equal to 9000 grams, but grams are not a part of the household measurement system

a) 9000 grams. b) 9000 ounces. c) 19.8 ounces. d) 19.8 pounds.

This leaves us with 19.8 lbs

HELP! I need some assistance

Answers

Answer:

I'm a Filipino hahahah I'm not

Um cubo fechado com 1 m3 de um líquido (d=0,8;  =21 000 kgf/cm2

) é submetido a um aumento de pressão de

20107 N/m2

. Calcule, no Sistema Internacional, as seguintes grandezas:

a) massa final;
b) peso final;
c) volume final;
d) massa volúmica final;
e) peso volúmico final.

Answers

Answer:

a. massa final

Explanation:

eu escolhi isso porque essa é a resposta espero que ajude você pode me dar uma ideia?

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