As a girl pushes and object across a wood floor she suddenly comes to an area where the floor has been waxed recently making it slippery . What becomes true if the coefficient of kinetic friction

Answers

Answer 1

Answer:

This question is incomplete but the completed question is below

As a girl pushes an object across a wood floor, she suddenly comes to an area where the floor has been waxed recently, making it slippery. What becomes true of the coefficient of kinetic friction? A. The coefficient of kinetic friction increases. B. The coefficient of kinetic friction decreases. C. The coefficient of kinetic friction becomes zero. D. The coefficient of kinetic friction becomes negative.

The correct option is B

Explanation:

Coefficient of kinetic friction can be defined as the frictional force resisted by the motion of an object. From the question, it might take the girl to apply a force equivalent to just half that of the weight of the object to overcome friction to keep the object moving on a wood floor. Once she gets to the waxed area, the frictional force reduces, thereby also reducing the coefficient of kinetic friction further. Thus, she will be able to use less than half of the force (equivalent to less than half of the weight of the object) to push the object.

Thus, the correct option is B.

Related Questions

. A car accelerates uniformly from 0 to 72 km/h in 11.5 seconds.
a) What is the acceleration of the car in m/s2? b) What is the position of the car by the time it reaches the velocity of 72 km/h?

Answers

Answer:

Explanation:

First job is to convert 72 km/hr to m/s:

[tex]72\frac{km}{hr}[/tex] × [tex]\frac{1000m}{1km}[/tex] × [tex]\frac{1hr}{3600s}[/tex] = 2.0 × 10¹ m/s

Now to find the acceleration which is

[tex]a=\frac{v_f-v_0}{t}[/tex] and filling in:

[tex]a=\frac{2.0*10^1-0}{11.5}=1.7\frac{m}{s^2}[/tex] That's part a. Part b want to know how far the car can get in 11.5 seconds (because that's the time it takes for the car to get to 72 km/hr). Since we know that the car can get 2.0 × 10¹ meters in 1 second, that means that in 11.5 seconds, the car can get 11.5(2.0 × 10¹) which is 230 meters.

What kind of waves are present during an earthquake?

Answers

Body Waves - Primary (P) & Secondary (S) Waves.
Surface Waves - Rayleigh & Love Waves.

Answer:

There are four main types of earthquake waves:

P-waves S-waves (which are body waves), Rayleigh waves Love waves (which are surface waves).

HOPE IT HELPS!!

This question is divided into two parts. This is part (a) of the question. A proton accelerates from rest in a uniform electric field of 580 N/C. At some later time, its speed is 1.00 x 106 m/s. (a) Find the magnitude of the acceleration of the proton. (Mass of the proton is 1.67 x 10-27 kg and charge is 1.60 x 10-19 C) (in the following options 10^10 m/s^2 is 1010 m/s2)

Answers

Answer:

The acceleration of proton is 5.56 x 10^10 m/s^2 .

Explanation:

initial velocity, u = 0

Electric field, E = 580 N/C

final speed, v = 10^6 m/s

(a) Let the acceleration is a.

According to the Newton's second law

F = m a = q E

where, q is the charge of proton and m is the mass.

[tex]a= \frac{q E}{m}\\\\a = \frac{1.6\times10^{-19}\times 580}{1.67\times 10^{-27}}\\\\a= 5.56\times 10^{10} m/s^2[/tex]

Look at the distance-time graph below. It shows Angela's journey as she walks to the end of the road and back. The end of the road is 40 m away. After how many seconds did she arrive back where she started?

Answers

Answer:

Explanation:

If the distance to the end of the road was 40 m, and she traveled back to where she started, she traveled a total distance of 80 m. It took her 100 seconds to travel the 80 m.

Based on the given distance-time graph, the number of seconds that Angela used to go to the end of the road and arrive back is 100 seconds.

How long did Angela take?

The end of the road is 40m and coming back is also 40 m. The total distance is:

= 40 + 40

= 80m

The graph shows that to walk 80 meters, Angela took a 100 seconds because the line on the graph ends at 80 m and 100 seconds.

Find out more uses of distance-time graphs at https://brainly.com/question/13877898.

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An object 2cm high is placed 3cm in front of a concave lens of focal length 2cm, find the magnification?

Answers

Answer:

0.4

Explanation:

A concave lens is a diverging lens, so it will always have a negative focal length. Image distance is always negative for a concave lens because it forms virtual images.

From the lens formula;

1/f = 1/u+ 1/v

- 1/2 = 1/3 - 1/v

1/v = 1/3 + 1/2

v= 6/5

v= 1.2 cm

Magnification = image distance/object distance

Magnification = 1.2cm/3cm

Magnification = 0.4

6. traction a. friction between a tire and the road.b. pushes a moving object out of a curve and into a straight linec. the ability of a car to hold a straight lined. a road higher in the center than on either edge 7. kinetic energy a.a force that keeps objects moving in a straightb. reduces the effects of inertiac. energy of motiond. a road higher in the center than on either edge 8. force of impact a. a force that keeps objects moving in a straight line.b. a road higher in the center than on either edgec. the force with which a moving vehicle hits another objectd. perception distance, reaction distance, and braking distance

Answers

Answer:

6. a. friction between a tire and the road

7. c. energy of motion

8. c. the force with which a moving vehicle hits another object

Explanation:

6. As a car moves along the road, the tires push back against the ground. As tires push back against the ground, the road exerts and opposing force to the motion of the tires. This opposing force is the friction between the tires and the road. This opposing force between the tires and the rad is called traction.

So, the answer is a

7. As an object moves, it has energy. This energy due to its motion is called kinetic energy.

So, the answer is c

8. When a moving vehicle hits another object, it exerts a force on the object. The process of the vehicle hitting the other object is called impact and the force exerted on the object is called the force of impact.

So, the answer is c.

Which describes an atom that has fewer neutrons than protons and more electrons than protons?

negative compound
positive compound
positive ion
negative ion

Answers

Answer:

Negative ion

.................

Negative Ion

An atom has fewer neutrons than protons and more electrons than protons is a negative ion

The force that the left team pulls with is 1000 N. If the right team's total mass is 300 kg and they accelerate by 1.2 m/s2, what is the force of resistance on the right team

Answers

Answer:

the force of resistance on the right team is 360 N

Explanation:

Given;

force of the left team, = 1000 N

total mass of the right team, m = 300 kg

acceleration of the right team, a = 1.2 m/s²

The force of resistance of the right team is calculated as;

Force = mass x acceleration

Force, F = 300 x 1.2

Force = 360 N

Therefore, the force of resistance on the right team is 360 N

why does a desert cooler cool better than a hot dry day

Answers

On a hot dry day, the amount of water vapour present in atmosphere is less. Thus, water present inside the desert cooler evaporates more, thereby cooling the surroundings more. Hence, a desert cooler cools better on a hot dry day.

A neutral object must have _______________ A. An equal amount of positive and negative charges B. no charges present at all C. more positive than negative charges D. more negative than positive

Answers

Answer:

Explanation:

Consider a question you may not have considered before. Suppose you have a mole of sodium in a container that contains nothing that it will react with. A mole of anything is 6.02 * 10^23 (in this case atoms).

Suppose that every one of those atoms has contributed 1 electron to something.

Do you think it would be safe to touch the container knowing that there are 6.02 * 10^23 positive charges all eager to get another electron, because they don't like repelling each other.

Safe or not? I'll give you a hint. A lightning bolt does not contain anywhere near 6.02*10^23 charges. No where near.

So -- since you never get a shock from just touching anything, There must not be electrons or ions present.

The answer is A

The answer to your question is A

A student sects a leaf of length 7.2 cm to draw. Her drawing is 28.8 cm in length. What is the magnification of the drawing?
a) x4
b) x207.36
c) x0.25
d) x36

Answers

Answer:

A) x4

Explanation:

Magnification is equal to image size divided by the actual size, or M = I/A.

The image size is the student's drawing, which is 28.8 cm, and the actual size is 7.2 cm. Divide them, and cancel out the units, and you should get:

28.8 cm/7.2 cm = 4

[tex]what \: is \: mirror \: {?}[/tex]

Answers

A thing that is made out of glass and you can see a yourself in

Eli states that sodium phosphate is a mixture because it is composed of both sodium ions and phosphate ions.

Which is the best analysis of Eli’s statement?

Answers

The question is incomplete, the complete question is;

Eli states that sodium phosphate is a mixture because it is composed of both sodium ions and phosphate ions. Which is the best analysis of Eli’s statement? It is correct because each ion is a pure substance, so sodium phosphate is made up of two pure substances. It is correct because the composition of sodium phosphate changes depending on the sample. It is incorrect because sodium phosphate is a compound that has a single composition. It is incorrect because the two types of ions in sodium phosphate cannot be seen.

Answer:

It is incorrect because sodium phosphate is a compound that has a single composition

Explanation:

A compound is a neutral substance made up of two or more atoms which are chemically combined together.

Ionic substances are made up of ions. These ions are not separate entities, they are part of the compound.

Hence, Eli's statement is incorrect because sodium phosphate is a compound that has a single composition.

In a science museum, a 130 kg brass pendulum bob swings at the end of a 14.4 m -long wire. The pendulum is started at exactly 8:00 a.m. every morning by pulling it 1.7 m to the side and releasing it. Because of its compact shape and smooth surface, the pendulum's damping constant is only 0.010kg/s. You may want to review (Pages 405 - 407) . Part A At exactly 12:00 noon, how many oscillations will the pendulum have completed

Answers

Answer:

The time in which the pendulum does a complete revolution is called the period of the pendulum.

Remember that the period of a pendulum is written as:

T = 2*pi*√(L/g)

where:

L = length of the pendulum

pi = 3.14

g = 9.8 m/s^2

Here we know that L = 14.4m

Then the period of the pendulum will be:

T = 2*3.14*√(14.4m/9.8m/s^2) = 7.61s

So one complete oscillation takes 7.61 seconds.

We know that the pendulum starts moving at 8:00 am

We want to know 12:00 noon, which is four hours after the pendulum starts moving.

So, we want to know how many complete oscillations happen in a timelapse of 4 hours.

Each oscillation takes 7.61 seconds.

The total number of oscillations will be the quotient between the total time (4 hours) and the period.

First we need to write both of these in the same units, we know that 1 hour = 3600 seconds

then:

4 hours = 4*(3600 seconds) = 14,400 s

The total number of oscillations in that time frame is:

N = 14,400s/7.61s = 1,892.25

Rounding to the next whole number, we have:

N = 1,892

The pendulum does 1,892 oscillations between 8:00 am and 12:00 noon.

You are accelerating upwards in an elevator when the net force on you increases. What happens to the acceleration

Answers

Answer:

the acceleration of the elevator is increasing

Explanation:

For this exercise we propose the solution using Newton's second law

F -W = m a

F = m (g + a)

If the net force increases, it implies that the acceleration of the elevator is increasing, since the acceleration of gravity is constant as the ascent is accelerating.

The boiling point of a substance is _72 degree Celsius. This temperature will be equivalent to Kelvin scale is-------.

Answers

Answer:

345 K

Explanation:

Temperature can be defined as a measure of the degree of coldness or hotness of a physical object.

Generally, it is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).

Given the following data;

Boiling point = 72°C

To convert the temperature in degree Celsius to Kelvin, we would use the following mathematical expression;

Kelvin = 273 + °C

Substituting into the formula, we have;

Kelvin = 273 + 72

Kelvin = 345 K

Therefore, the temperature of 72°C will be equivalent to 345 K on the Kelvin scale.

What do you think Jose’s grandmother meant by saying that the bread was too dense? What other things can you think of that are “dense”?

Answers

The bread was most likely heavy

Answer:

What I think that Jose's grandmother meant by saying that the bread was too dense is that she thinks the bread is too heavy or it can even mean to be too compacted in substance. The matter in the bread are close together and not spread out like in the air, when the matter in the air starts to come closer together it starts to make fog, because it is becoming more dense. Some more things that are heavy or dense are things like a big stereo speaker, an anvil, or even a big piece of wood used to build.

Explanation:

Calculate surface tension of an enlarged radius of 4cm to 6cm and amount of work necessary for enlargement was 1.5×10^-4 joules

Answers

Answer:

[tex]T=7.5*10^{-5}[/tex]

Explanation:

From the question we are told that:

Radius [tex]r=2cm[/tex]

Work done [tex]W=1.5×10^-4 joules[/tex]

Generally the equation for Work done is mathematically given by

[tex]W=T.dA[/tex]

Therefore

[tex]T=\frac{W}{dr}[/tex]

[tex]T=\frac{1.5*10^{-4}}{2}[/tex]

[tex]T=7.5*10^{-5}[/tex]

A pair of forces with equal magnitude, opposite directions, and different lines of action is called a "couple." When a couple acts on a rigid object, the couple produces a torque that does not depend on the location of the axis. The drawing shows a couple acting on a tire wrench, each force being perpendicular to the wrench. Determine an expression for the torque produced by the couple when the axis is perpendicular to the tire and passes through the following. Express your answers in terms of the magnitude F of the force and the length L of the wrench.

Answers

The drawing shows the couple acting on a tire wrench is missing and so i have attached it.

We are to find an expression for the torque when the axis is perpendicular to the tire and passes through the points A, B & C

Answer:

Point A: τ = Fl

Point B: τ = 0

Point C: - Fl

Explanation:

Formula for torque is;

τ = F × d

Where;

F is perpendicular force

d is distance.

Thus;

> At point A, it means we are taking torque about point A and so we have;

τ = (-F × 0) + (F × L)

τ = Fl

> At point B, it means we are taking torque about point B and so we have;

τ = (-F × L/2) + (F × L/2)

τ = -(FL/2) + (FL/2)

τ = 0

> At point C, it means we are taking torque about point C and so we have;

τ = (-F × L) + (F × 0)

τ = -FL

Two parallel conducting plates are separated by 12.0 cm, and one of them is taken to be at zero volts. (a) What is the magnitude of the electric field strength between them, if the potential 5.6 cm from the zero volt plate is 450 V

Answers

Answer:

-8.036 kV/m

Explanation:

The electric field E = -ΔV/Δx where ΔV = change in electric potential = V - V' where V = electric potential at x = 5.6 cm = 450 V and V' = electric potential at x = 0 cm, = 0 V . So, ΔV = V - V' = 450 V - 0 V = 450 V.

Δx = distance between the 0 V plate and the 450 V point = 5.6 cm = 0.056 m

So, E = -ΔV/Δx

Substituting the values of the variables into the equation, we have

E = -ΔV/Δx

E = -450 V/0.056 m

E = -8035.7 V/m

E = -8.0357 kV/m

E ≅ -8.036 kV/m

Since the electric field between two parallel conducting plates is constant, the electric field between the plates is E = -8.036 kV/m

Capacitance (C) is measured in farads, where 1 farad is equivalent to 1 coulomb per volt. Resistance (R) is measured in ohms, and 1 ohm is equal to 1 volt per ampère. The coulomb is defined as the amount of charge passing when a current of 1 ampère flows for 1 second. What is the unit of RC expressed in its simplest form?

Answers

Ahhh ok so much better now I got a good day amp a Relationship was the day amp the

When fundamental units are combined, they result in derived units. RC (which means Resistance Capacitance) is a derived unit and its unit in the simplest form is Coulomb per Ampere (C/A)

Given that:

Capacitance (C) [tex]\to[/tex] Farads (f)

and

[tex]1f = 1\frac CV[/tex] ----- 1 farad = 1 capacitance per volt

Resistance (R) [tex]\to[/tex] Ohms [tex]\Omega[/tex]

[tex]1 \Omega = 1\frac{V}{A}[/tex]

The unit of RC is the product of the unit of R by the unit of C.

i.e.

[tex]RC = 1f \times 1\Omega[/tex]

Substitute [tex]1f = 1\frac CV[/tex]

[tex]RC = 1\frac CV \times 1\Omega[/tex]

Substitute [tex]1 \Omega = 1\frac{V}{A}[/tex]

[tex]RC = 1\frac CV \times 1\frac VA[/tex]

Cancel out volts (V)

[tex]RC = 1\frac CA[/tex]

[tex]\frac CA[/tex] means Coulomb per Ampere

Hence, the unit of RC is Coulomb per Ampere.

Answers

Answer:

shushhhgggvvv vgfxgh

Explanation:

gey laahhg

211.2kg i looked it up

As a main sequence star exhausts hydrogen in its core, its surface becomes ___ and its energy output per second (luminosity) becomes ____.

Answers

Answer:

Explanation:

Please answer will mark brainleist

Answers

[tex]option \: (a) \: is \: correct.[/tex]

Explanation:

Yes, I was wrong. Pressure increases as the area decreases.

As per the Figure A, the truck is so heavy and having a greater mass. So, the area of contact between the tyres and the road increases and decreases it's pressure on the road due to the increase in area.

As per the Figure B, You know the nature of Tomato that it is soft and smooth to touch and also lighter mass when it's compared with the truck. As it having a lighter mass, it can be cut through the sharp knife. The area of contact decreases and pressure increases on the vegetables.

Answer:

Option number B

Explanation:

The pressure is indirectly proportional to the area therefore pressure decreases when the area increases, and pressure increases when the area decreases

A gas is enclosed in a confainer fitted with a piston of cross sectional area 0.10 the pressureof the gas is maintained in 8000 when hat is slowlh transferred the piston is pushed up through a distance of 4.0cm If 42j of heat is transferred to the system during expansion wht is the change im internal energy of th system

Answers

Answer:

10 Joule

Explanation:

The solution and answer are well written in the Pic above.

When the spacecraft is at the halfway point, how does the strength of the gravitional force on the spaceprobe by Earth compre with the strength

Answers

Solution :

When the spacecraft is at halfway point, the distance from the Earth as well as Mars are same. We have to account the masses of the planets. The gravitational force that is exerted by the Earth is greater because of its combined mass with the space probe.

The mass of Earth is greater than the mass of Mars. Therefore, the force of Earth is more than Mars.

3. Thekinetic energy of an object of
mass, m moving with a velocity
of 5 ms-t is 25 J. What will be its
Toinetic energy when its velocity
is doubled? What will be its
Icinetic energy ruhen its velocity
is increased three times?

Answers

Answer:

1. 100 J

2. 225 J

Explanation:

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

Velocity (v) = 5 ms¯¹

Kinetic energy (KE) = 25 J

Mass (m) =?

KE = ½mv²

25 = ½ × m × 5²

25 = ½ × m × 25

25 = 25m / 2

Cross multiply

25m = 25 × 2

25m = 50

Divide both side by 25

m = 50 / 25

m = 2 Kg

1. Determination of the kinetic energy when the velocity is doubled.

Mass (m) = 2 Kg

Velocity (v) = double the initial velocity

= 2 × 5 ms¯¹

= 10 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 10²

KE = ½ × 2 × 100

KE = 100 J

2. Determination of the kinetic energy when the velocity increased three times.

Mass (m) = 2 Kg

Velocity (v) = three times the initial velocity

= 3 × 5 ms¯¹

= 15 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 15²

KE = ½ × 2 × 225

KE = 225 J

Internal energy of a diatomic gas consists of:
OA. kinetic energy due to vibration and rotation.
B. kinetic energy due to translation, vibration, and rotation.
C. potential energy due to intermolecular forces.
D. kinetic energy due to translation only.

Answers

Answer:

C) Potential energy due to intermolecular forces.

5- Clasifica los siguientes cambios de la materia, anotando delante de cada uno cambio físico (F) o cambio químico (Q): • Disolver azúcar en agua • Freir una chuleta • Arrugar un papel • El proceso de la digestión • Secar la ropa al sol • Congelar una paleta de agua • Hacer un avión de papel • Oxidación del cobre • Romper un lápiz • Prender fuegos artificiales • Excavar un hoyo • Quemar basura

Answers

Answer:

1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.

2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.

3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.

4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.

5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.

6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.

7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.

8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.

9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.

10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.

11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.

12) Quemar basura - Cambio químico - Reacción de combustión.

Explanation:

A continuación, veremos que representa cada caso: