Chiếu tia sáng lên một gương phẳng biết góc tới bằng 15⁰ hãy tính góc phản xạ bằng bao nhiêu

Answers

Answer 1

Answer:

góc phản xạ 15°

Explanatin


Related Questions

In a democracy how is rule of law regarded

Answers

Answer:

It is respected as leaders are accountable to the people. The rule of law within a democratic country will dictate what actions is considered wrong and punishable to do in that country. This will prevent people from harming and violating each other to get what they want and form a stable and safe society

Which of the following travels with a wave?
O A. Energy only
O B. Matter only
O C. Neither matter nor energy
O D. Both matter and energy

Answers

Answer:

A. Energy only is the answer to your question

The mass of a brick is 2kg. Find the mass of water displaced by it when it is completely immersed in water. (Density of the bricks is 2.5 g/cm^3)​

Answers

Answer:

2000g

Explanation:

volume=mass/density

=2000/2.5

=800cm³

mass=density×volume

=800×2.5

=2000g

49. A block is pushed across a horizontal surface with a
coefficient of kinetic friction of 0.15 by applying a
150 N horizontal force.
(a) The block accelerates at the rate of 2.53 m/s2
Find the mass of the block.

(b) The block slides across a new surface while
experiencing the same applied force as before.
The block now moves with a constant speed.
What is the coefficient of kinetic friction between
the block and the new surface?

Answers

Answer:

(a) 37.5 kg

(b) 4

Explanation:

Force, F = 150 N

kinetic friction coefficient = 0.15

(a) acceleration, a = 2.53 m/s^2

According to the newton's second law

Net force = mass x acceleration

F - friction force = m a

150 - 0.15 x m g = m a

150 = m (2.53 + 0.15 x 9.8)

m = 37.5 kg

(b) As the block moves with the constant speed so the applied force becomes the friction force.

[tex]F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4[/tex]

An egg is dropped onto a wood floor and breaks. When a different egg (same mass) is dropped the same distance onto a foam pad on the wood floor, it does not break. Why (in terms of physics) does this happen?
A. The pad extends the time so the impulse changes.
B. An egg requires a harder surface so it won’t break.
C. The pad pulls the egg to the floor.
D. Wood is harder than the pad.

Answers

Answer:

A.

Explanation:

The pad extends the time so the impulse changes.

Answer:

A. The pad extends the time so the impulse changes

Explanation:

in term of physics it has same mass:)

a uniform meter ruler is balanced at its midpoint

Answers

Answer:

a) i) x = 0.25 m, ii) x = 0.10 m, iii)  x = 0.050 m

b) i)  x = 0.40 m

Explanation:

a) For this exercise we use the rotational equilibrium equation, where we assume that the anticlockwise rotations are positive.

1) L = 2W  

we set our reference system in the center of the bar where the fulcrum is

              ∑τ = 0

              W 0.50 - L x = 0

              x = 0.50 W / L

we substitute the value

              x = 0.50 W / 2W

              x = 0.25 m

ii) L = 5W

we calculate

              x = 0.50 W / 5W

              x = 0.10 m

iii) L = 10 W

               x = 0.50 W / 10W

              x = 0.050 m

b) a new weight is placed at x₂ = 30 cm on the left side

              W 0.50 + W 0.30 - L x = 0

              x = (0.50 + 0.30) W / L

              x = 0.80 W / L

we calculate

i)  L = 2W

                x = 0.80 w / 2w

                x = 0.40 m

The summer camps had a field trip from the campus to Fragrance Hill. They traveled at an average speed of 65 km/h in the first 2 hours. After that, traveled at another average speed of 78 km/h. If the distance between the campus and Fragrance Hill is 364 km, what was the total time for the field trip?

Answers

Answer:

Explanation:

They traveled this distance in 2 parts, essentially. Part 1 had an average speed for a certain number of hours, part 2 had an average speed for a certain number of hours, and those 2 parts taken together took them a distance of 364 km. In equation form, that looks like this:

km/hr part 1 + km/hr part 2 = 364 km

Now we need to find each part on the left side of that equation. Part 1 first:

We traveled 65 km/hr for 2 hours, so that took us

[tex]65\frac{km}{hr}*2hr[/tex] and canceling out the hour label, we have that in part 1 we got

65(2) = 130 km. Good. Now onto the second part, where our unknown is.

We traveled 78 km/hr the second part for x hours, so that took us

[tex]78\frac{km}{hr}*xhr[/tex] and canceling out the hour label, we have that in part 2 we got

78x km. Now we can fill in the main equation (the one in bold print)

130 km + 78x km = 364 km and subtracting 130 km from both sides:

78x km = 234 km and dividing by 78 km:

x = 3 hours. Part 2 took 3 hours. Part 1 took 2 hours, so the whole trip took 5 hours.

what is electricity???????​

Answers

Explanation:

Electricity is defined as the rate of flow of charges in a conductor.

hope it helps.stay safe healthy and happy...

Answer:

Electricity is the presence and flow of electric charge. Using electricity we can transfer energy in ways that allow us to do simple chores . it's best - known form is the flow of electrons through conductor such as copper wires. The world "electricity " is sometimes used to mean "electrical energy "

Explanation:

hope it is helpful to you

[tex]kavya[/tex]

Compared with dim light, what do light waves that look bright tend to have the subject just says science but the picker doesn't have that

Answers

Answer:

The brightness of a light depends on the amplitude of the light wave, which is the extent the waves moves from their equilibrium position. The brightness is also related to the amount of light that is emitted or reflected by an object

Therefore, compared to dim light, light that look bright have a higher amplitude and emit or reflect more light energy (photons)

Explanation:

Water exits straight down from a faucet with a 1.96-cm diameter at a speed of 0.55 m/s. The volume flow rate of the water as it exits from the faucet is Blank
1. Calculate the answer by read surrounding text. cm3/s. As the water falls from the faucet with the given speed, it accelerates due to gravity and reaches a speed of _______
2. Calculate the answer by read surrounding text. after it has moved 0.2 m downward. With this change in speed of the water, the diameter of the stream 0.2 m below the faucet is _______
3. Calculate the answer by read surrounding text. _________ cm.

Answers

Answer:

Q = 165.95 cm³ / s,  1)    v = [tex]\sqrt{0.55^2 + 19.6 y}[/tex],  2)  v = 2.05 m / s,

3)  d₂ = 1.014 cm

Explanation:

This is a fluid mechanics exercise

1) the continuity equation is

         Q = v A

where Q is the flow rate, A is area and v is the velocity

         

the area of ​​a circle is

        A = π r²

radius and diameter are related

        r = d / 2

substituting

       A = π d²/4

       Q = π/4   v d²

let's reduce the magnitudes

       v = 0.55 m / s = 55 cm / s

let's calculate

       Q = π/4   55   1.96²

       Q = 165.95 cm³ / s

If we focus on a water particle and apply the zimematics equations

        v² = v₀² + 2 g y

where the initial velocity is v₀ = 0.55 m / s

        v = [tex]\sqrt{0.55^2 + 2 \ 9.8\ y}[/tex]

        v = [tex]\sqrt{0.55^2 + 19.6 y}[/tex]

2) ask to calculate the velocity for y = 0.2 m

        v = [tex]\sqrt{0.55^2 + 19.6 \ 0.2}[/tex]

        v = 2.05 m / s

3) We write the continuous equation for this point 2

        Q = v₂ A₂

        A₂ = Q / v₂

let us reduce to the same units of the SI system

        Q = 165.95 cm³ s (1 m / 10² cm) ³ = 165.95 10⁻⁶ m³ / s

        A₂ = 165.95 10⁻⁶ / 2.05

        A₂ = 80,759 10⁻⁶ m²

area is

        A₂ = π/4   d₂²

        d₂ = [tex]\sqrt{4 A_2 / \pi }[/tex]

        d₂ = [tex]\sqrt{ \frac{4 \ 80.759 \ 10^{-6} }{\pi } }[/tex]

        d₂ = 10.14 10⁻³ m

        d₂ = 1.014 cm

Performance Task 2: "TAKE HOME TASK
1. It took scientist a long time to reconcile the dual nature of light, which led to the idea of the duality of matter. To further see an
evidence of this concept try to observe the smoke coming from a barbeque drill. From a distance, you will see a
wave flow of smoke going up.
Guide Questions:
a. Look closely into it, what do you see?
ha Does your observation tell something about the dual nature of matter? Why? Why not?
2. Observe the colors on the soap bubbles on the surface of water.
Guide Questions:
a. What do you see?
b. What property of light is exhibited?

Pasagot po huhu

Answers

I am dum sorry .........

Which of the following measures does not help promote technological progress?


issuing a patent to a company that invents a new product


increased wages for researchers


training programs for workers


reducing the scale of the market for a new product

Answers

Answer:

reducing the scale of the market for a new product

Explanation:

A product can be defined as any physical object or material that typically satisfy and meets the demands, needs or wants of customers. Some examples of a product are mobile phones, television, microphone, microwave oven, bread, pencil, freezer, beverages, soft drinks, automobiles, motorcycles, etc.

The use of technology in the manufacturing of a new product can be effectively and efficiently promoted in the market by doing the following;

I. Issuing a patent to a company that invents a new product. Patent can be defined as the exclusive or sole right granted to an inventor by a sovereign authority such as a government, which enables him or her to manufacture, use, or sell an invention for a specific period of time.

Generally, patents are used on innovation for products that are manufactured through the application of various technologies.

II. Paying a higher amount of money as wages for researchers who are saddled with the responsibility of making finding about a product.

III. Creating a training programs that would help to improve on the knowledge and skills of workers.

However, reducing the scale of the market for a new product in comparison with other products and standards does not help promote technological progress.

The moon is 250,000 miles away. How many feet is it from Earth? (dimensional analysis)

Answers

Answer:

1.261 billion

Explanation:The distance between the earth and the moon in miles is 250,000,so in feet,The distance is 1.261 billion

ANSWER ASAP What happens to a circuit’s resistance (r) , voltage (v) , and current (l) when you decrease the length of the wire in the circuit ?
A . R decreases
V constant
l increases

B . R constant
V increases
l increases

C . R increases
V constant
l decreases

D . R increases
V decreases
I decreases

Answers

Answer:A

Explanation:i just took the test

2(a)
A car accelerates from 22ms^-1 to 43ms*-1 in 18.6 seconds.
(a) Calculate the acceleration of the car.
2(b)
Find the distance covered by the car in 10 seconds.

2(c) Find the velocity after 5 seconds.

Answers

Answer:

2a.

a=1.13ms^-2

2b.

S=277m

2c.

V=27.7ms-¹

Explanation:

Initial Velocity (U)=22m/

Final Velocity (V)=43m/

Time(t) =18.6s

a. a=V-U/t

a=43-22/18.6

a=1.129

a=1.13m/

2b.

S=ut+1/2 at²

s=22(10)+1/2×1.13(10)²

s= 220+0.57(10)²

s= 220+0.57(100)

s= 220+57

s=277m

2c.

V=U+AT

V=22+1.13(5)

V=22+5.65

V=22+5.7

V=27.7m/

Which of the following describes a sound wave?
A. Longitudinal wave that does not require a medium
c
B. Longitudinal wave that requires a medium
C. Transverse wave that does not require a medium
D. Transverse wave that requires a medium

Answers

The correct answer is B, sound waves are longitudinal with a medium

An unbalanced 6.0-newton force acts eastward on an object for 3.0 seconds. The impulse
produced by the force is
18 N:s east
2 Nós east
18 N:s west
2 Nis west

Answers

c. 18 N:s West ksmxmak kxkammxj kan

2 What are(i) free fall , (ii) acceleration due to gravity, (iii) escape velocity , (iv) centripetal force?​

Answers

Answer:

Explanation:

1. Free fall implies an object falling under the gravitational influence only. During the flight, no other force acts on it except the gravitational pull.

2. Acceleration due to gravity is the earth's natural force of pull on all objects on its surface, close to its surface, or in the region where the force can be felt. This force pulls object to the surface of the earth.

3. Escape velocity is the required minimum velocity for an object to leave the gravitational influence of the earth. It has a constant value which can be determined by;

Escape velocity = [tex]\sqrt{2gR}[/tex]

where g is the gravitation force of the earth and R is the radius of the earth.

4. Centripetal force is the force of pull that is required to keep a rotation object in its curved path.

What animal would your trapezius muscles look like if you concentrated on working it out

Answers

Answer:

If you went to work your trap muscles you don't need a ton of fancy gym equipment. Here are four trapezius exercises you can perform using your own body.

pushupshrupupright rowshoulder blade squeeze

Which statement should he place in the region marked X?

Answers

Explanation:

The answer is Electrons move between objects.

Chỉ ra kết luận đúng trong các kết luận sau:



A.
Chỉ có các hạt mang điện tích dương chuyển động có hướng mới tạo ra dòng điện.

B.
Chỉ có các hạt mang điện tích âm chuyển động có hướng mới tạo ra dòng điện.

C.
Khi nguyên tử chuyển động có hướng thì xuất hiện dòng điện.

D.
Các dụng cụ điện sẽ hoạt động khi có dòng điện chạy qua.

Answers

it should be c! hope this helps

TRUE OR FALSE. When non-conservative forces are present, the amount of work done increases with the length of the path.

Answers

Answer:

True

Explanation:

When non-conservative forces are present, the amount of work done increases with the length of the path, this is true because, when a force is applied, the force does when and the non-conservative forces also do work. Since the non-conservative force work against the force  applied, this tend to increase the net work done by the applied force to compensate for the loss in energy due to the work done by the non-conservative forces.

57. A red ball (m= 10 kg) is moving at 3 m/s. A green ball (m = 8 kg) is moving at 3.5 m/s. Which ball has more
energy and by how much (2)

Answers

Answer:

the green ball has 4J more energy

Explanation:

The kinetic energy is given by the formula

K = 0.5 m v^2

the kinetic energy of the red ball:

K(red) = 0.5*10*3^2= 45J

of the green ball:

K(green)=0.5*8*3.5^2 = 49J

therefore the green ball has more energy by 4 Joules

Question 4(Multiple Choice Worth 3 points)
(03.02 MC)

Which statement best reflects a change in weather?

Today is cloudy, but tomorrow will be clear and sunny.
The average rainfall has decreased over the past five years.
Ocean temperatures are projected to increase over time.
Glaciers are melting more rapidly now than in the past 100 years.
plzzz helpppp asap

Answers

Answer:

a is your answer.............

A cricket player lowers his hands while catching the ball. wny?​

Answers

because maybe the ball was going downwards or he was getting ready to catch the ball. one of those 2.

write any two features of capital​

Answers

Capital has several important characteristics that are as follows:
Capital is a Passive Factor.
Capital is Man-Made.
Capital is not Indispensable.
Capital has high mobility.
Capital is Elastic.
Capital Depreciates.
Capital is Productive.
Capital is Temporary in Nature.

which best esplains how the body maintains homeostasis.
a. All systems work together to stabilize the body .
b. Each systems work indepently to stabilize the body .
c. All systems works together to match the external environment.

​d. Each system works indepently to match the external evironment.

Answers

a. all systems work together to stabilize the body

All systems work together to stabilise the body!!

When an object is in a gravitational field, it has energy in its __________ __________ energy store.

Answers

Answer:

Gravitational potential

Explanation:

Any object that is not on the surface of the Earth, but at a height instead has potential energy. Eventually, this can become kinetic energy once the object falls.

When an object is in a gravitational field, it has energy in its gravitational potential energy store.

2. A student is pulling a 11.0 kg sled along flat ground. The students 30.0 kg sister then sits in the sled. The student then applies a 430 N force at an angle of 35° N of E. If the force of friction is 180 N, what is the acceleration of the sister sitting in the sled. (Ensure you draw a free body diagram.)

Answers

Answer:

Explanation:

The equation for this is

F - f = ma

The thing that gets strange here is that, because the student is pulling his sister on the sled with the rope at an angle, some of his efforts are being wasted. The sled is only going to move forward (horizontally), so the vertical component of that force is useless. He's not actually pulling horizontally with that much force; we have to figure out how much using the following equation:

[tex]F=430cos35[/tex] to get that

F = 352 N

Everything else falls into place quite easily into the equation now:

352 - 180 = 41a and

172 = 41a so

a = 4.2 m/s/s

what is measurment ?​

Answers

Answer:

Measurement is the act or the process of finding the size, quantity or degree of something.

Explanation:

We can measure the length, weight, and capacity (volume) of any given object.

The process of comparing an unknown quantity with a known standard quantityis called as measurement.
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