Lợi ích của lực ma sát và cách làm tăng

Answers

Answer 1
Ma sát có lợi và cách tăng ma sát: Ma sát giữa bánh xe với mặt đường, giữa đế giày với mặt đất, ma sát khi ta cầm một vật là ma sát có lợi. Làm tăng ma sát bằng cách tăng áp lực, tăng độ nhám của mặt tiếp xúc ( cắt nhiều khía ở vỏ xe, đế giày, rải cát trên đường trơn)


Related Questions

1. If the mass of an object is measured in kg and the velocity is measured in m/s, what is the unit for momentum?​

Answers

The unit for momentum is equal to Kgm/s.

Given the following data:

Unit of mass = Kilogram (kg).Unit of velocity = meter per seconds (m/s).

To determine the unit for momentum:

What is momentum?

In Science, momentum can be defined as a multiplication of the mass of an object and its velocity.

Mathematically, momentum is giving by this formula;

[tex]Momentum = mass \times velocity[/tex]

Substituting the given parameters into the formula, we have;

[tex]Momentum = kg \times m/s\\\\[/tex]

Momentum = Kgm/s.

Read more on momentum here: brainly.com/question/15517471

What force would be required to accelerate a 1,100 kg car to 0. 5 m/s2? N.

Answers

Answer:

550 N

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question

mass = 1100 kg

acceleration = 0.5 m/s²

We have

force = 1100 × 0.5 = 550

We have the final answer as

550 N

Hope this helps you

Answer:

If your filling in the blank on edge then its 550

Explanation:

PLEASE ANSWER ASAP
A 5 kg bowling ball traveling at 2 m/s hits a motionless 10 kg bowling ball. If the smaller ball bounces back at a speed of -1 m/s, what will be the speed of the larger ball after the collision?

Answers

Hi there!

Recall the conservation of momentum:

m1v1 + m2v2 = m1v1' + m2v2'

Let m1 = 5 kg ball and m2 = 10 kg ball

Since m2 is at rest, we can rewrite:

m1v1 = m1v1' + m2v2'

Plug in the given values:

5(2) = 5(-1) + 10v2'

Solve for v2':

10 = -5 + 10v2'

15 = 10v2'

15/10 = 1.5 m/s

Given ↷

m1 =5kgm2=10( since it's at rest)v1=2m/sv2=0(since it's at rest)v1' = -1To find ↷the speed of the larger ball after the collisionSolution↷

We know that,

m1v1 + m2v2 = m1v1' + m2v2'

5 x 2 + 0 = 5 x -1 + 10 x v2'

10= -5 +10 x v2'

15 = 10 x v2'

v2' = 15/10

v2' = 1.5 m/s

hence , the speed of the larger ball after the collision will 1.5m/s

If the resistor is connected in series, the voltage across the wire changes. (true or false)

Answers

true, Resistors connected in series always have equivalent resistance greater than any individual resistor. brainlessly please
Resistors in Series carry the same current, but the voltage drop across them is not the same as their individual resistance values will create different voltage drops across each resistor as determined by Ohm's Law ( V = I*R ).

A child is stationary on a swing.(a)The child is given a push by his brother to start him swinging.His brother applies a steady force of 84 N over a distance of 0.25 m.(i) Calculate the work done by this force.(2)..............................................................................................................................................(ii) State how much energy is transferred by this force.(1)..............................................................................................................................................(iii) After several more pushes, the child has a kinetic energy of 71 J.The mass of the child is 27 kg.Show that the velocity of the child at this point is about 2.3 m/s.(2)(iv) Which one of these quantities changes in both size and direction while he is swinging?Put a cross ( ) in the box next to your answer.(1)Ahis gravitational potential energyBhis momentumCthe force of gravity acting on himDhis kinetic energy

Answers

Answer:

Work done = Fs

Explanation:

(i) W = Fxs

= 84N x0.25m

= 21 Joules

(ii) Ek = 1/2mv^2

71 = 1/2×27×v^2

71×2/27 = v^2

v = 23m/s

The work done by this force is 21 Joule.

Energy transferred by the force is 21 Joule.

The boy's momentum changes periodically, that is,  in both size and direction.

What is force?

An external force is an agent that has the ability to change the resting or moving condition of a body. It has a direction and a magnitude. So, it is  a vector quantity. Newton is the SI unit of force (N).

(i) Given parameter:

Steady force applied by his brother, F = 84 N.

Displacement, d = 0.25 m.

The work done by this force, W = F.d = 84×0.25 = 21 Joule.

(ii) Amount of work done is transferred by this force as an energy. So, amount of energy transferred by the force is 21 Joule.

(iii) Given parameter:

Mass of the child, m= 27 kg.

Kinetic energy, E = 71 J.

Let, velocity of the child = v, then kinetic energy is,

E = 1/2 × mv²

⇒ v = √(2E/m)

= √(2×71/27)

= 2.3 m/s.

Hence, the velocity of the boy is 2.3 m/s. (proved).

(iv) During swing, his velocity changes periodically. That's why, his momentum changes periodically, that is,  in both size and direction.

Learn more about force here:

https://brainly.com/question/13191643

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How much force is needed to accelerate a 70 kg rider and the 200kg motorcycle the
rider is on at 4m/s?

Answers

Answer:   F = (200 kg + 70 kg) * 4 m/s² = 270 kg* 4m/s² = 1080 N

Answer:

F = 1080 N

Explanation:

please answer this don't go on the one which is choosed coz i bymistakely choosed it​

Answers

Answer:

(B) B is travelling fastest

Explanation:

slope of xt graph = speed.

Slope of B is greater than a and c.

BRAINLIST PLS

Image credit: The Hubble Heritage Team (AURASTSCI/NASA)
To which category does galaxy #2 belong? Why does it belong in this category?
WRITER

Answers

Can i ask u a question

how to do the next ques for more

Brainliest me please

If a 5.00 kg box slides down a ramp inclined at 60.0° above the horizontal, what is the

acceleration of the box

Answers

Answer:

A 70 kg box is slid along the floor by a 400 n force. The coefficient of friction between the box and the floor is 0. 50 when the box is sliding

What event has inspired your life so far? How has this event changed you?

Easy pts! I will give Brainliest. :)

Answers

the art event called “cant help myself” its very emotional if you understand it :)

An object with a mass of 90 grams, moving at a constant velocity of 6 meters per second, has __________. A. A momentum of 540 gram meters per second B. An acceleration of 10 meters per second squared C. A momentum of 90 gram meters per second D. An acceleration of 6 meters per second squared Please select the best answer from the choices provided. A B C D.

Answers

Answer: 540 g m/s.

Explanation:

Answer: A.

A momentum of 540 gram meters per second!

Explanation: On Edge!!

A fan operating at 260V with a current being supplied at 13A. What is the effective resistance at which it is being operated?

Answers

Answer:

20 ohms

Explanation:

Resistance=Potential difference÷Electric current

X=260÷13

X=20

A crate of mass 50kg is pulled up a rough inclined plane, inclined at an angle of 60° to the horizontal. Determine the total work done in moving the crate to the top of the inclined 200m high.​

Answers

Answer:

Wc = m*g = 50kg * 9.8N/kg = 490 N = Wt.

of crate.

Fc = 490N  60o = Force of crate.

Fp = 490*sin60 = 424.4 N. = Force

parallel to incline.

Fv = 490*cos60 = 245 N. = Force perpendicular to the incline.

Ff = u*Fv = u*245 = Force of friction.

Fap-Fp-Ff = m*a

Fap-424.4-u*245 = m*0 = 0

Fap = 424.4 + 245u. = Force applied.

L = 200m/sin60 = 231 m. = Length of

incline.

Work = Fap * L=(424.4+245u) * 231.

Explanation:

How to find resistance

Answers

Answer:

R = V/I

Explanation:

Example:

V = IR

R = V/I

If we were to use V = 120 and I = 0.25

R = 120/0.25

R = 480 Ohms

Your resistence would equal Ohms

HELP PLEASE
2. What is the potential energy of a 2000 g basketball that is stuck on the rim of a 3m hoop?

Answers

Answer:

[tex]U_g=58.86 J[/tex] or [tex]U_g=60 J[/tex]

Explanation:

Answer is attached. I do not know if you needed to use 9.81 or 10 for the acceleration due to gravity, so both solutions are attached.

A taxi is travelling at 20 m/s. Its driver accelerates with acceleration 5 m/s2 for 4 s. What is its new velocity?​

Answers

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

the homogenvity of s=ut+1/2at^2

Answers

s = ut+(1/2)at² is dimensionally homogeneous.

What substance is a polymer found in nature?

Answers

Silk,wool, DNA, cellulose and protein

hello could some one please help me wit these

Answers

Answer:

1.D 2.A 3.A 4.B 5.C 6.A 7.A 8.A

Explanation:

Answer:

Question one is: kinetic energy

Question two is: tin

Question three is: zinc

Question four is: compression stroke

Question five is: second law of thermodynamics

Question six is: Convection

Question seven is: refrigerater

Explanation:

The next page called use vocabulary

the answers:

Question twenty three is: Heat engine

Question twenty four is: Thermodynamics

Question twenty five is: solar collector

Question twenty six is: specific heat capacity

Question twenty seven is: a conductor

Question twenty eight is: it's total energy increasing

Question thrity is: internal combustion engine

Question thrity one is: Exhaust stroke

Question thrity two is: plastic

Question thrity three: I don't know this one sorry!

Question thrity four is: Temperature

Question thrity five is: Heat

Hope his helps!!! <3

How long will it take to travel 150km at an average speed of 40 km/h

Answers

Answer:

6,000 minutes

Explanation:

To calculate distance u multiply speed and time or speed and rate

The following diagram shows a person exerting a
300.-newton force on the handle of a shovel that
makes an angle of 60. with the horizontal ground.

Determine the magnitude of the component of the
force perpendicular to the ground.

Answers

Answer:

260 Newtons

Explanation:

Okay, so what you have to do is know what the question is asking. It wants to know the force perpendicular to the ground. We know perpendicular makes a right angle, so we use the diagram to make it into a right triangle with a degree of 60, and hypotunese of 300 newtons. Now, we use basic trigonometry, we place x on the horizontal side since it perpendicular to the ground. We know it´s sin because x is opposite to 300 which is the hyp.

Sin= opp/hyp

x/300

sin(60)= x/300

300*sin(60)= 259.8, which rounds to

260 Newtons

There is your answer :D. Happy to help.

The component of the force which is perpendicular to the ground is → F [y] = 261 a[y].

What are the components of a Vector?

A vector V making an angle θ with the x - axis, can be resolved into two two components along the x and y - axes respectively as →

V = Vcosθ a[x] + Vsinθ a[y]

where -

a[x] is the unit vector along the +x axis

a[y] is the unit vector along the +y axis.

Given is a force of magnitude 300 N acting on the handle that makes an angle of 60° with the horizontal ground.

The component normal to the ground will be the component along the  y - axis. The component along the y - axis is the sine component. Suppose that vector F represents the force of magnitude (|F|) 300 N. The component perpendicular to the ground will be -

F [y] =  |F| sinθ a[y]

F [y] = 300 x sin(60°)  a[y]

F [y] = 300 x 0.87

F [y] = 261 a[y]

Therefore, the component of the force which is perpendicular to the ground is → F [y] = 261 a[y].

To solve more questions on Vector Resolution, visit the link below-

https://brainly.com/question/27199886

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

Answers

Answer:

yeah

Explanation:

Helllo, hope you are doing well :)

help with this question

Answers

Answer:

D and B.

Explanation:

The wavelength must be taken from the same corresponding point. D and B are both at the crests of a wave, with no other crests in between, which means the distance between them is equal to one wavelength.

Science Questions :)

Answers

I’m pretty sure it’s diagonally down to the right? Just seems the most logical to me anyways.

Answer:

The box will move diagonally down to the right

Consider the dot diagrams for Objects A, B, and C. The arrow-
represents the direction of motion. Match the motion of
Objects A, B, and C to one of the lines on the graph.
Numbers can be used only one time.
A
2
B
Pos'n
3
С
-t
Tap
A matches graph:
B matches graph:
C matches graph:
4
5
6
--
Pos'n
t

Answers

You throw a ball upward. (a) Draw a motion diagram and two force diagrams for the ball on its way up and another motion diagram and two force diagrams for the ball on its way down. (b) Represent the motion of the ball with a position-versus-time graph and velocity-versus-time graph.

A deer runs 5 km through the woods in 9 min and then walks 7 km in 2 hours. Find its average speed in km/h.

Answers

First, it was running at 33.3 km/h.
Then, he was walking at 3.5 km/h.

thus averaging a speed of 18.4 km / h

A boy drops a stone in a well and finds it takes 2.60 seconds to hit the water.
A) How deep is the well?
B) With what speed does the stone hit the water?

Answers

Answer:

(i) How deep is the well (Height)

=> t = √(2H/g)

=> √2H = t × g

=> 2H = t² × g²

=> 2H = (2.60)² × (10)²

=> 2H = 6.76 × 100

=> 2H = 676

=> H = 676 ÷ 2

=> H = 338 m

(ii) speed of the stone:

=> v = √(2Hg)

=> v = √(2 × 338 × 10)

=> v = √6760

=> v = 26√10 m/s

What are nucleic acids, and what are their function and structure? Give an example

Answers

1) Nucleic acids are macromolecules that store genetic information and enable protein production.


2) Their function and structure is carry genetic information which is read in cells to make the RNA and proteins by which living things function.

There are no risks when taking medication to treat anxiety.


Please select the best answer from the choices provided.

T
F

Answers

Answer:

False

Explanation:

Answer:

The answer is False

Explanation:

NEED ANSWER ASAP!
Which statement about a converging lens is not correct?

A ray parallel to the principal axis of the lens is refracted through the principal focus.

B All rays of light refracted by the lens pass through the principal focus.

C The distance between the centre of the lens and the principal focus is the focal length

D The principal focus of the lens is a point on the principal axis.​

Answers

Geometric optics allows you to find which the correct answer about which false statement is:

  B)  All rays of light refracted by the lens pass through the principal focus.

Geometric optics studies the formation of images using the light geometric properties of optical systems, the main expression for this is:

      [tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]  

Where f is the focal length, p and q the distance to the object and the image respectively.

There are some points of special interest:

Object at infinity (p = ∞).  In this case of the expression we see that the image is at the focal length. Image at infinity (q = ∞). In this case the object is at the focal point.

Let's analyze the claims.

A) True. A parallel ray comes from infinity and the image is formed at the focal point.

B) False. The image point is given by the expression above and depends on the distance to the object.

C) True. This is the definition of focal length.

D) True. All distances are measured from the main axis.

In conclusion, using geometric optics we can find that the correct answer about which false statement  is:  

      B)  All rays of light refracted by the lens pass through the principal focus.

Learn more about geometric optics here: brainly.com/question/2548694

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