Lợi ích của lực ma sát và cách làm tăng

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

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

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.

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.

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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Answer:

(B) B is travelling fastest

Explanation:

slope of xt graph = speed.

Slope of B is greater than a and c.

BRAINLIST PLS

Answer:

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

Hope this helps you

Answer:

If your filling in the blank on edge then its 550

Explanation:

Answer: 540 g m/s.

Explanation:

Answer: A.

A momentum of 540 gram meters per second!

Explanation: On Edge!!

Answer:

yeah

Explanation:

Answer:

6,000 minutes

Explanation:

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

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].

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-

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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:

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

Can i ask u a question

Brainliest me please

The unit for momentum is equal to Kgm/s.

Given the following data:

To determine the unit for 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

Answer:

The box will move diagonally down to the right

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

Silk,wool, DNA, cellulose and protein

Answer:

False

Explanation:

Answer:

The answer is False

Explanation:

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

Answer:

F = 1080 N

Explanation:

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:

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

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

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.

Answer:

20 ohms

Explanation:

Resistance=Potential difference÷Electric current

X=260÷13

X=20

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

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