Which best describes reflection and refraction?

In both reflection and refraction, rays pass through a boundary.
In both reflection and refraction, rays bounce off a boundary.
In reflection, rays bounce off a boundary, and in refraction, rays pass through a boundary.
In refraction, rays bounce off a boundary, and in reflection, rays pass through a boundary.

Answer:

105 m

Explanation:

Given that the initial velocity of the body, u= 50 m/s in upward direction.

Acceleration due to gravity, g= 10 m / [tex]s ^ 2[/tex] in the downward direction.

Let h be the height of the body when the velocity of the body is 20 m/s.

As the gravitational force acting in the downward direction, so taking it negative as

a= - 10 m/[tex]s ^ 2[/tex]  in the upward direction.

By using the equation of motion [tex]v^2=u^2+2as[/tex] ...(i)

Here, u= 50 m/s

v= 20 m/s

[tex]a=- 10 m/s^2[/tex]

s=h

Putting all the values in the equation (i), we have

[tex]20^2=50^2+2(-10)h \\\\400=2500-20h \\\\h=\frac{2500-400}{20} \\\\h=105 m[/tex]

Hence, the height of the body is 105 m.

Answer: true

Explanation:

If the scale model was working as it was predicted to work, then the final product is expected to be flawless. It should be a reasonable product if the scale model is working. Our answer is the option True.

The net force on the block acting perpendicular to the incline is

∑ F = n - w cos(29.4°) = 0

where n is the magnitude of the normal force and w = m g is the weight of the block.

The equation itself comes from splitting up the forces acting on the block into components pointing parallel or perpendicular to the incline. The only forces acting on the block in the perpendicular direction are the normal force and the perpendicular component of the block's weight.

Solve for n :

n = m g cos(29.4°)

n = (6 kg) (9.80 m/s²) cos(29.4°)

n ≈ 51.2 N

Given :

[tex]m_1 = 82 \ kg\\\\v_1 = 257 m/s\\\\m_2 = 60 kg[/tex]

Let, us assume that momentum is conserved during the process.

To Find :

The velocity [tex]v_2[/tex] .

Solution :

Applying conservation of momentum :

Initial momentum = Final momentum

[tex]m_1v_1 = m_2v_2\\\\82\times 257=60\times v_2\\\\v_2 = \dfrac{82\times 257}{60}\ m/s\\\\v_2 = 351.23\ m/s[/tex]

Hence, this is the required solution.

Answer: Well the answer is KE = 5.625E-7 i just don't know the units for it...

Hope this helps....... Stay safe and have a Merry Christmas!!!!!!!!!! :D

Answer:

3.2

Explanation:

I remember taking this quiz and I think that one is correct

Answer:

The work done by Ramas is 3920 N.

Explanation:

Given;

mass of the load lifted by Ramas, m = 20 kg

height through which the load is lifted, h = 20 m

The work done by Ramas is equal to gravitational potential due to the height in which the load is lifted.

W = PE = mgh

where;

g is acceleration due to gravity = 9.8 m/s²

W = 20 x 9.8 x 20

W = 3920 N.

Therefore, the work done by Ramas is 3920 N.

Answer:

a. Vf = 39.24 [m/s]

b. Vf = 31.24 [m/s]

c. Vf = 47.24 [m/s].

Explanation:

To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.

[tex]v_{f}=v_{o}+g*t[/tex]

where:

Vf = final velocity [m/s]

Vo = initial velocity = 0 (when the rock is dropped)

g = gravitational acceleration = 9.81 [m/s²]

t = time = 4 [s]

a.

[tex]v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s][/tex]

b.

In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.

[tex]v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s][/tex]

The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.

c.

[tex]v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s][/tex]

Answer:

Explanation:

The mass of the object can be found by using the formula

[tex]m = \frac{p}{v} \\ [/tex]

p is the momentum

v is the velocity

From the question we have

[tex]m = \frac{56.59}{5.3} \\ = 10.677358...[/tex]

We have the final answer as

Hope this helps you

Answer:

Therefore, the work done to lift a 20 kg sack of potatoes of potatoes vertically 6.5 m is 1, 274 J.

Answer:

zero

Explanation:

this is the answer

Answer:

b

Explanation:

The phrase that describes blackbody radiation is the radiation that is absorbed by an object as it warms.

Blackbody radiation is a radiation produced by heated objects, particularly from a blackbody.

In physics, a blackbody, approximated by a hole in a hollow black sphere, absorbs all incident electromagnetic radiation and reflects none.

Therefore, the phrase that describes blackbody radiation is the radiation that is absorbed by an object as it warms.

Learn more about blackbody radiation at: https://brainly.com/question/13934832

#SPJ2

Note that when the ball is in the air, the only force acting on it is the downward pull of gravity, so the force of the swing is a red herring.

The ball hits the ground at the same height from which it was hit, so its final velocity will have the same magnitude of 49 m/s, but pointing at an angle of 35° below the horizontal.

Sry,I only know the answer of q2

Chlorine is a non metal because it is bad conductor of heat and sodium is a metal because it is good conductor of heat.

The 3 ways in which metal is different from non metal are given below:

1)metal are good conductor of heat but nonmetal are bad conductor of heat.

2)metals are malleable but non metal aren't malleable.

3)metals are generally ductile but non metal aren't ductile.

Hope it will helpyou!

Answer:

Explanation:Chlorine is a non metal because it is bad conductor of heat and sodium is a metal because it is good conductor of heat.

The 3 ways in which metal is different from non metal are given below:

1)metal are good conductor of heat but nonmetal are bad conductor of heat.

2)metals are malleable but non metal aren't malleable.

3)metals are generally ductile but non metal aren't ductile

Answer:

ν=293.53 Hz

Explanation:

ν= speed/λ

speed = 204 m/s

λ=0.695 m

v = 204 m/s * 1/0.695m

meters cancels out

1/s = Hz

v = 204/0.695 Hz

ν=293.53 Hz

please give thanks, click heart! :)

apparently it is wrong, but my work and online calculator says otherwise... possibly round your answer? I'm not sure then...

Answer:146.75

Explanation:

Answer:

(1) chess is played by him

(2) The great black engine was seen by her

(3) Arrangements for functions had been made by him

(4) A meeting is being attended by Raman

= when the last of the guests left, I went back into the hall to look for my mobile phone that I had kept on the table, I found that my mobile phone was not there. I felt freaked and I asked to every member of my family about my phone, but nobody had idea about that. then there was a phone call made by my uncle to my father, that his son had taken the mobile by mistake. After sometime, My uncle came to return my mobile. Then I took a sigh of relief .

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Answer:

vibrate

Explanation:

Vocal folds vibrate when excited by aerodynamic phenomena; they are not plucked like a guitar string. Air pressure from the lungs controls the open phase. The passing air column creates a trailing “Bernoulli effect,” which controls the close phase.

hope it helps!!

Answer:

10 m/s

Explanation:

Speed = Distance / Time

Speed = 400 / 40

Speed = 10

Unit = meters per second = m/s

Answer:

A & D

Explanation:

A single-displacement reaction is a chemical reaction whereby one element is substituted for another one in a compound and thereby generating a new element and also a new compound as products.

From the options, only options A & D fits this definition of single-displacement reactions.

For option D: Both left and hand and right hand sides each have one element and one compound. We can see that K is substituted from KBr to join Cl to form KCl and Br2 on the right hand side.

For option A: Both left and hand and right hand sides each have one element and one compound. We can see that OH is substituted from 2H2O to join Mg to form Mg(OH)2 and H2 on the right hand side.

The other options are not correct because they don't involve only and element and a compound on each side of the reaction.

Answer:

W = MG

750 = M * 10

M = 750/10

M = 75 kg

Answer:

76.479 Kilograms Force (kgf)

Explanation:

Answer:

[tex]F_{g}=7.4704\times10^{-5}[/tex]

Explanation:

Givens: d = 1.0 × [tex]10^{4}[/tex]  [tex]m_{1} = 4.0 x 10^{8}[/tex]  [tex]m_{2} = 2.8[/tex]×[tex]10^{5}[/tex]

Required: [tex]F_{g}=?[/tex]

Formula:  [tex]F_{g}= \frac{(6.67x10^{-11})(m_{1})(m_{2}) }{d^{2}}[/tex]    (6.67x10^-11  is the gravitational constant)

[tex]F_{g}=\frac{\left(6.67\cdot10^{-11}\right)\left(4.0\cdot10^{8}\right)\left(2.8\cdot10^{5}\right)}{\left(1.0\cdot10^{4}\right)^{2}}[/tex]

[tex]F_{g}=7.4704\times10^{-5}[/tex]

Answer:

See explanation

Explanation:

From Newton's law; the rate of change of momentum is proportional to the impressed force. Hence;

F.t = mv- mu

F= force

t= time

m= mass

V= final velocity

u = initial velocity

since u = 0, mv= 0

F= MV/t

F= 69.8 × 5.27/0.833

F= 442 N

Impulse = Ft= 442 × 0.833= 368 Ns

Answer:

4s

Explanation:

My assumption would be 4s since 25 going into 100 would be 4? hope that helped..

Answer:

a. t = 2.02 s

b. d = 20.2 m

Explanation:

Horizontal Motion

If an object is thrown horizontally from a height h with a speed v, it describes a curved path ruled exclusively by gravity until it eventually hits the ground.

The time the object takes to hit the ground can be calculated as follows:

[tex]\displaystyle t=\sqrt{\frac{2h}{g}}[/tex]

The time does not depend on the initial speed.

The range or maximum horizontal distance traveled by the object can be calculated by the equation:

[tex]\displaystyle d=v.t[/tex]

The man standing on the edge of the h=20 m cliff throws a rock with an initial horizontal speed of v=10 m/s.

a.

The time taken by the rock to reach the ground is:

[tex]\displaystyle t=\sqrt{\frac{2*20}{9.8}}[/tex]

[tex]\displaystyle t=\sqrt{4.0816}[/tex]

t = 2.02 s

b.

The range is:

[tex]\displaystyle d=10\cdot 2.02[/tex]

d = 20.2 m

Answer:

F = 159.07 N

Explanation:

Given that,

Mass of a tennis ball, m = 54.9 g = 0.0549 kg

It accelerates from rest to a speed of 45.1 m/s.

The impact with the racket gives the ball a constant acceleration over a distance of 35.1 cm = 0.351 m

We need to find the magnitude of net force acting on the ball.

Let a be the acceleration of the ball. Using third equation of motion to find it.

[tex]v^2-u^2=2ad\\\\a=\dfrac{v^2-u^2}{2d}\\\\a=\dfrac{(45.1)^2-(0)^2}{2\times 0.351}\\\\=2897.45\ m/s^2[/tex]

Net force,

F = ma

F = 0.0549 kg × 2897.45 m/s²

= 159.07 N

Hence, the net force acting on the ball is 159.07 N.

Answer:

Vr = 20 [km/h]

Explanation:

In order to solve this problem, we have to add the relative velocities. We must remember that velocity is a vector, therefore it has magnitude and direction. We will take the sea as the reference measurement level.

Let's take the direction of the ship as positive. Therefore the boy moves in the opposite direction (Negative) to the reference level (the sea).

[tex]V_{r}=30-10\\V_{r}=20 [km/h][/tex]

Explanation:

list in order with the smallest molecules at the top and largest molecules at the bottom:

1.Oxygen

2.Water

3.Carbon dioxide

4.amino acid

5.Glucose

6. Starch

7. Protein

The molecules can be arranged as follows with the smallest at the top is oxygen, water, carbon dioxide, amino acid, glucose, starch, protein.

The given molecules;

starch, water, glucose, carbon dioxide, protein, amino acid, oxygen

The molecular weight of the given compounds is listed as follows;

water -------- 18 g/mol

glucose -------  180.2 g/mol

starch (2 or more glucose) ------ 360 g/mol

carbon dioxide ------ 44 g/mol

protein -------- 20,000 g/mol

amino acid (glycine) ----- 75 g/mol

oxygen -------- 16 g/mol

Thus, the molecules can be arranged as follows with the smallest at the top;

Learn more here:https://brainly.com/question/19537339

Answer:

310 N

Explanation:

The net force, I assume, is an applied force that is causing motion of the crate. However, frictional force opposes this motion, so the frictional force is in the opposite direction. Overall, we can create a net force equation of this crate as

Fnet= Force applied + Force of friction

Thus,

Fnet= 375N -65N (because friction is in the opposite direction)

Then solve to get that the net force while the crate is in motion is 310N.

Answer:

When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J

Explanation:

Kinetic Energy

Is the type of energy an object has due to its speed. It's proportional to the square of the speed.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

The object has a kinetic energy of K=25 J when moving at v=5 m/s, thus the mass can be calculated by solving for m:

[tex]\displaystyle m=\frac{2K}{v^2}[/tex]

[tex]\displaystyle m=\frac{2*25}{5^2}=2[/tex]

m = 2 Kg

If the speed is doubled, v=10 m/s, the new kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}2\cdot 10^2[/tex]

K = 100 J

If the speed is tripled, v=15 m/s, the new kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}2\cdot 15^2[/tex]

K = 225 J

When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J