a rectangular block has the density of 350g/cm3 the dimensions are 3.5 6.cm 2.5
cm calculate the mass of the bock​

Answers

Answer 1

Answer:

18375g

Explanation:

[tex]\boxed{density = \frac{mass}{volume} }[/tex]

[tex]∴ mass = density \times volume[/tex]

Let's find the volume of the rectangular block.

Volume

= length ×breadth ×height

= 3.5 ×6 ×2.5

= 52.5cm³

Mass of the block

= 350(52.5)

= 18375g


Related Questions

A ball rolling down a hill with a speed of 8 m/s has 139 J of kinetic energy. What is it's mass in kg?

Answers

Explanation:

Velocity of ball (v) = 8 m/sKinetic Energy (K.E) = 139 JMass (m) = ?

We know that,

• K.E = ½mv²

→ 139 = ½ × m × (8)²

→ 139 = ½ × m × 64

→ 139 = 1 × m × 32

→ 139 ÷ 32 = m

4.34 kg = m

Therefore, mass in kg is 4.34 kg.

Which of the following statements is NOT true of a hypoosmotic solution?
A. It is also known as a hypotonic solution.
B. There are more dissolved solids within the cell than outside the
cell.
C. It may cause water to move into the cell, which will cause it to
swell.
D. It may cause the cell to shrink or crenate.

Answers

There are more dissolved solids within the cell than outside thecell.

Answer:

Good luck on the test, you donuts.

Explanation:

How do I solve this problem

Answers

Answer:

it is light

Explanation:

the arrow that says light is on the glass it must be near from tungsten

A crane is lifting a 500 lb piano with a velocity of 2fts''. Express the power of the crane in hp. (1 hp = 550ft-lbs)​

Answers

Answer:

goalindia

goalindiaGiven:

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kg

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 W

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F⇒ v = P/mg

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F⇒ v = P/mg⇒ v = 1357.72/(226.8 × 9.8)

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F⇒ v = P/mg⇒ v = 1357.72/(226.8 × 9.8)⇒ v = 1357.72/2222.64

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F⇒ v = P/mg⇒ v = 1357.72/(226.8 × 9.8)⇒ v = 1357.72/2222.64⇒ v = 0.61 m/s

goalindiaGiven:Mass of car, m = 500 lb = 500 × 0.4536 = 226.8 kgPower output of crane, P = 1.82 hp = 1.82 × 746 = 1357.72 WTo Find:The velocity of the car.Calculation:- The Power can be given by the formula:P = F × v⇒ v = P/F⇒ v = P/mg⇒ v = 1357.72/(226.8 × 9.8)⇒ v = 1357.72/2222.64⇒ v = 0.61 m/s- So, the velocity of the car will be 0.61

Blonde hair is produced by inheriting double recessive alleles (bb) from one’s parents. What is the probability of their offspring having blonde hair?
plz help

Answers

Answer:

over 50% power ability

Explanation:

I believe it's half and half chance that The Offspring or the child will have that trait

a bicycle uniformly from rest at time t the velocity of the bicycle is v at what time will the bicycle have a velocity of 4v​

Answers

Here

Acceleration and initial velocities are constant.

According to first equation of kinematics.

[tex]\\ \sf\longmapsto v=u+at[/tex]

[tex]\\ \sf\longmapsto v=0+at[/tex]

[tex]\\ \sf\longmapsto v=at[/tex]

[tex]\\ \sf\longmapsto v\propto t[/tex]

Time was t at velocity vTime will be 4t at velocity 4v

C. Answer the following questions.
1. Define Earthquake. Write any 3 precautions during earthquake

Answers

Answer:

1. An earthquake is a sudden violent shaking of the ground, typically causing great destruction, as a result of movements within the earth's crust or volcanic action. 2. (3 precautions during an earthquake are)... If you are indoors take cover under a desk, Stay away for glass doors, windows or outside doors and finally drop down or hold on to something until the shaking stops.

Hope that helped?

Explanation:

What can happen when untreated sewage water contaminates water?

Answers

Answer:

Health Effects

Life-threatening human pathogens carried by sewage include cholera, typhoid and dysentery. Other diseases resulting from sewage contamination of water include schistosomiasis, hepatitis A, intestinal nematode infections, and numerous others.

Explanation:

BRAINLIEST PLEASE • •

︴︴

____

if a current of 2.0 A is flowing from point a to point b, the potential difference between Vb- Va (in V) is:


a. 6
b. 8
c. -6
d. -8
e. 22

Answers

Answer:

[tex]\huge\color{skyblue}\boxed{\colorbox{black}{Answer ☘}}[/tex]

[tex]total \: resistance \: ( R_{t} ) = (3 + 1)ohm \\ (since \: the \: resistors \: are \: connected \\ in \: series)[/tex]

[tex]current \: flowing \: through \: circuit(I) = 2A \\ \\ now... \: by \: ohms \: law \\ V = IR\\ V = (2)(4) \\ = > 8v[/tex]

therefore , option (b) is correct!!

hope helpful~

How do you measure a English saddle to fit your horses?

Answers

Answer:

measure the area in which the rider will sit on, then take those measurements to a person who crafts saddles, tell them the exact measurements. then you wait a while until he/she is done then put the saddle on the horse.

Explanation:

Answer:

Explanation:

The shape of the horse's withers is also a determining factor in choosing a saddle. An adjustable hoop saddle allows you to choose with finesse the opening of the tree at the height of the withers, in order to best adapt to each horse. It is the size of the arch that determines the opening of the saddle.

English saddles are the main riding saddles used in equestrian disciplines around the world: Show jumping, endurance, require specific designs to meet specific needs. For example, dressage saddles are designed to bring the rider closer to the horse, allowing him to communicate very precisely with his horse.

what are the applications of triangle law of forces​

Answers

Answer:

The triangle law of forces can also be stated as. if a body is in equilibrium under the action of three forces acting at a point, then the three forces can be completely represented by the three sides of a triangle taken in order. A body might be subjected to further than one force at a similar time.

Explanation:

Hope it's help

A book is at rest on a flat table. The book is pushed across the table, causing it to move
and eventually come to rest again. How does the potential and kinetic energy change
during this process? (1 point)
The potential and kinetic energy will stay the same unless the book speeds
up or slows down
The potential energy increases as the book is pushed across the table.
The kinetic energy stays the same.
The potential energy will stay the same as long as the book stays on the
table. The kinetic energy increases as the book is pushed across the table.
The potential and kinetic energy decreases as the book comes to rest
again

Answers

Answer:

Explanation:

As no altitude or mass changed, the potential energy remained constant.

The potential energy will stay the same as long as the book stays on the

table.

Kinetic energy went from zero at rest to a positive value while moving, and then returned to zero when the book was at rest again.

The kinetic energy increases as the book is pushed across the table.

A car accelerating from rest for 20s to reach velocity of 15 m/s and it keeps on. moving with this velocity for 50s an then it applied the break
Stop in 30s what is the displacement?

WILL GIVE BRAINLY best answer with steps

Answers

Answer:

1125m

Explanation:

The car moves with a uniformly accelerated motion for 20s:

s = 1/2·a·t² + v0·t + s0 (note that vo = 0 and s0 = 0, with v0 being the initial velocity and s0 the initial displacement).

So: s = 1/2·a·t²

The acceleration will be: Δv/Δt = 15m/s / 20s = 0.75 m/s²

s1 = 1/2·0.75 m/s² · (20 s)^2 = 150m

Then it continues with the velocity he acquired (v = a·t = 0.75 m/s²·20s = 15 m/s):

s2 = vt = 15m/s·50s = 750m

The final acceleration, when stopping, will be:

a = Δv/Δt = -15m/s / 30s = -1/2 m/s²

s3 = 1/2·(1/2m/s²)·(30s)² = 225m.

Now we sum s1 with s2 and s3:

s1 + s2 + s3 = 150m + 225m + 750m = 1125m

Zoe is setting up a track for a toy car. The track has a ramp that is 32° above horizontal. If Zoe wants the car to travel as a projectile for 1.0 seconds, how fast does the toy car need to be moving as it leaves the ramp?
4.9 m/s
1.0 m/s
9.2 m/s
7.4 m/s m

Answers

Answer:

Explanation:

Not enough information.

IF we ASSUME she wants the car to be at LAUNCH LEVEL after 1 second of flight.

THEN

The highest point will have zero vertical velocity and will have taken ½ second to get there. This means that the initial vertical velocity was

v = gt

vy₀ = 9.8(0.5)

vy₀ = 4.9 m/s

vsinθ = vy₀

v = vy₀/sinθ

v = 4.9/sin32

v = 9.2466...

v = 9.2 m/s

A 4.0-mF capacitor initially charged to 50 V and 6.0-mF capacitor charged to 30 V are connected to each other with the positive plate of each connected to the negative plate of the other. what is the final charge of the 6.0-mF capacitor?

a. 20 mC
b. 8.0 mC
c. 10 mC
d. 12 mC
e. 230 mC

Answers

[tex]\huge\color{pink}\boxed{\colorbox{black}{Answer ☘}}[/tex]

12 mC

Explanation:

We are given that...

[tex]C_{1} = 4mF \\ V_{1} = 50v \\ C_{2} = 6mF \\ V_{2} = 30v \\ \\ we've \: to \: find \: the \: final \: charge \: on \: the \: 6mF \\capacitor \:- \\ \\ we \: know \: that ,\: \\ Q = CV \\ \\ using \: the \: formula \: \\ Q_{1} = 4 \times 50 = 200mC \\ Q_{2} = 6 \times 30 = 180mC \\ \\ total \: charge , \: Q_{1} - Q_{2} = 200 - 180 = 20mC \\ \\ let \: V \: be \: the \: final \: potential \: \\ 4V + 6V = 20mC\\ 10V = 20mC \\ V = \frac{20}{10} = 2V \\ final \: charge \: Q = CV = 6 \times 2 = 12mC[/tex]

therefore,

σptíσn ( d ) íѕ cσrrєct!

hope helpful~

~Be Brainly!

What capacitance is needed to store 3μC of charge at a voltage of 120V?

Answers

Answer:

 C = 0.025F

Explanation:

Charge =q=3×[tex]10^{-6}[/tex]C

Voltage=V=120V

Q=CV

C=Q/V

   =3×[tex]10^{-6}[/tex]/120

   =1/40×[tex]10^{-6}[/tex]

        C = 0.025F

         C=2.5 [tex]10^{-4}[/tex]C  0r  25 ×[tex]10^{-3}[/tex]F

7. Which of the following explains how radiometric dating is used to estimate absolute
age.
a. By comparing how deep in the curst the radioactive material in a sample of rock
is, scientists can calculate the length of time since the rock formed.
b. By comparing the amount of organic material in a sample of rock, to the known
rate of decay of the parent rock, scientists can calculate the length of time since
the rock formed.
C. By comparing the amount of radioactive material in a sample of rock, to the
surrounding rocks, scientists can calculate the length of time since the rock
formed.
d. By comparing the amount of a radioactive material in a sample of rock, to the
know rate of decay of the parent rock, scientists can calculate the length of time
since the rock formed.

Answers

Answer:

d.

Explanation:

Radiometric dating is a method of dating geological/ archaeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample. Carbon dating is a form of radiometric dating, but, in choice b, you're not comparing the carbon to the rock. One would compare ¹⁴C levels within the organic compound, just as one would compare radioactive isotope levels in a rock.

Please help me answer the following question!

What is the momentum of a 750-kg Volkswagen Beetle when at rest?
Please give the Value and Unit

Answers

Answer:

P = 0

Explanation:

Momentum is defined as the quentity of motion contained in a body. Mathematically, it can be defined as the product of mass and velocity. So, in order to determine the Volkswagen Beetle, at rest, we can use the simple formula, as follows:

where,

P = Momentum of Volkswagen Beetle = ?

m = Mass of Volkswagen Beetle = 750 kg

v = Velocity of Volkswagen Beetle = 0 m/s (since, it is at rest)

Therefore,

P =

The part of the moon that is visible will appear to grow and shrink during the lunar cycle. This occurs in the direction of _____ to _____.

Answers

Answer:

left to right

Explanation:

give me brain pls

Answer:

of the moon to .......

Which degree would a person most likely pursue if they are interested in how
computers work to solve problems?
A. Business management
B. Mechanical engineering
C. Computer science
D. Education technology
SUBMIT

Answers

Answer:

Computer science

Explanation:

You would get everything you need to know about computers if you took computer science. I hope this helps

Answer:

Computer science

Explanation:

Cats are groomed often by their owners to remove hair. What logical inference can be made based on this statement?

Answers

Answer:

its keeps the fur straight.....im kinda confused with the question

Explanation:

1. An airplane flies with an airspeed (speed relative to the air) of 215
km/h. The wind is blowing at 45.0 km/h. Find the velocity of the
plane (relative to the ground) if the plane is pointed straight west and
the wind is:

A. blowing toward the
west (3 points)

B. blowing toward the east (3 points)

C. blowing toward the south (4 points)
(For part C be sure to calculate the angle as well.)

Answers

Answer:

Explanation:

A) 215 + 45.0 = 260 km/h West

B) 215 - 45.0 = 170 km/h West

C) √(215² + 45.0²) = 219.6588... 220 km/h

θ = arctan(45.0/215) = 11.8214... 11.8° S of W

The airplane's ground velocity is westward at 170 km/h regardless of wind direction. The south wind does not affect the plane's westward velocity in component C.

Vector addition will determine each scenario's plane velocity relative to the ground. We'll simplify by assuming a consistent horizontal breeze.

Let's divide the airplane's velocity and wind velocity into westward (negative) and eastward (positive) components.

Data: Plane airspeed = 215 km/h.

45 km/h wind.

A. West wind:

The airplane's westward (negative) ground velocity:

West aeroplane velocity = -215 km/h

-45 km/h west wind.

Find Vg when the wind blows west:

Vg (west) = Aeroplane velocity + Wind velocity (west)

Vg(west) = -215 km/h - (-45 km/h)

Vg (west)=-170 km/h

B. East wind: 2. Westward (negative) aeroplane velocity relative to the ground:

West aeroplane velocity = -215 km/h

Wind velocity (east) = 45 km/h (because the wind is blowing eastward)

Find Vg when the wind blows east:

Vg (west) = Aeroplane velocity (west) + Wind velocity (east).

Vg (west) = -215 + 45 km/h

Vg (west)=-170 km/h

C. Southerly wind: 3. Westward (negative) aeroplane velocity:

West aeroplane velocity = -215 km/h

Wind velocity (south) = 0 km/h (no effect since wind is not moving westward)

Find Vg when the wind blows south:

Vg (west) = Aeroplane velocity (west) + Wind velocity (south).

Vg (west) = -215 + 0 km/h.

Vg (west)=-215 km/h

All resultant velocities are westward and 170 km/h.

Part C's plane's westward velocity is unaffected by the south wind. The plane's ground velocity remains -215 km/h (westward). Since the heading is westward, no angle is needed.

To know more about velocity

https://brainly.com/question/80295

#SPJ2

HELP ME the mean free path λ and the mean collision time τ of the molecules of a diatomic gas of molecular mass 6.00 × 10⁻²⁵ kg and radius r = 1.0 x 10⁻¹⁰ m are measured. From these microscopic data can we obtain macroscopic properties such as temperature T and pressure P? If so, consider λ = 4.32 x 10⁻⁸ m and τ = 3.00 x 10⁻¹⁰ s and calculate T and P.

Answers

The temperature of the diatomic gas is 300.5 K and the pressure is 5.33 atm.

The given parameters;

Mass of the gas molecules, m = 6 x 10⁻²⁵ kgRadius of the gas, r = 1 x 10⁻¹⁰ mMean free path, [tex]\lambda_{rms}[/tex] = 4.32 x 10⁻⁸ mMean collision time, [tex]\tau = 3 \times 10^{-10} \ s[/tex]

The mean velocity of the gas molecules is calculated as follows;

[tex]\tau = \frac{\lambda _{rms}}{V_{rms}} \\\\V_{rms} = \frac{\lambda _{rms}}{\tau} \\\\V_{rms} = \frac{4.32 \times 10^{-8} }{3 \times 10^{-10}} \\\\V_{rms} = 144 \ m/s[/tex]

The temperature  of the gas molecules is calculated as follows;

[tex]V_{rms} = \sqrt{\frac{3kT}{M} } \\\\V_{rms}^2 = \frac{3kT}{M} \\\\T = \frac{V_{rms} ^2 M}{3k}[/tex]

where;

k is Boltzmann constant

[tex]T = \frac{V_{rms} ^2 M}{3k} \\\\T = \frac{(144)^2 \times (6.0 \times 10^{-25})}{3 \times 1.38 \times 10^{-23}} \\\\T = 300.5 \ K[/tex]

The number of gas molecules per unit volume is calculated as follows;

[tex]\lambda = \frac{1}{4\pi \sqrt{2} \ r^2 n} \\\\n = \frac{1}{\lambda 4\pi \sqrt{2} \ r^2} \\\\n = \frac{1}{(4.32 \times 10^{-8}) \times 4 \pi \times \sqrt{2} \ \times (1\times 10^{-10})^2} \\\\n = 1.303 \times 10^{26} \ molcules/m^3[/tex]

The pressure of the gas molecule is calculated as follows;

[tex]n = \frac{P}{kT} \\\\P = nkT\\\\P = (1.303 \times 10^{26} ) \times (1.38 \times 10^{-23}) \times (300.5)\\\\P = 540,341.07 \ Pa\\\\P = 5.33 \ atm[/tex]

Thus, the temperature of the diatomic gas is 300.5 K and the pressure is 5.33 atm.

Learn more about mean free path of gases here: https://brainly.com/question/4279093

How much work is done on a 30 kg object when 20 Newton’s of force is exerted for a distance of 5 meters

Answers

Answer:

Work = force * displacement

= 50 N * 20 Meter

=1000 Newton meter = 1000 joule .

Explanation:

Which variable mentioned in Table 2-1 is kept constant? a. amount of time spent swimming b. type of swimming stroke c. number of calories used d. the person swimming

Answers

Answer:

a. amount of time spent swimming

Ben (55kg) is standing on very slippery ice when Junior (25kg) bumps into him. Junior was moving at a speed of 8m/s before the collision. Find the speed of ben and junior as they move across the ice after the collision. Give the answer in m/s. Describe the work you did to get the answer

Answers

Answer:

2.5m/s

Explanation:

m1=55kg

m2=25kg

Ben's velocity before collision=0m/s

Junior's velocity before collision= 8m/s

P1=m1v1+m2v2

P1=55kg(0m/s)+25kg(8m/s)

P1=200kg(m/s)

Know that the momentum before the collision = momentum after the collision

P2=(55kg+25kg)V

200kg(m/s)=(75kg)V

200kg(m/s)/75kg=V

V=2.5m/s.

It makes sense bc after they collide, their speed would slow down, and it wouldn't make sense if the momentum would be greater or less after they collide.

Who did the ram caught in the thicket (Genesis 22:13) represent?

Answers

Answer:

I think the answer is goat

3 materials that are denser than water and 3 that arent denser than water

Answers

Answer:

denser than water:

1. clay

2. coins

3. rock

aren't denser than water

1. wood

2. sponge

3. apple

please help me !!
Gymnasts often practice on foam floors, which increase the collision time when a gymnast falls. What effect does this have on collisions?
A. The change in momentum needed to stop the gymnast is increased.
B. The change in momentum needed to stop the gymnast is decreased.
C. The force exerted by the floor on the gymnast decreases.
D. The force exerted by the floor on the gymnast increases.

Answers

The correct answer is B

A change in momentum is also called:
a. Impact
b. Imput
c. Impulse
d. Impole

Answers

Answer:

c. Impulse

Explanation:

Other Questions
Need some help :( A)12.7B)13.3C)12.4 which part lets you point to objects on your screen, click on them, and even move them? What is the force applied to a baseball that has a mass of 142kg and has a acceleration of 30m/s to the power of 2 After nitrogen becomes part of the lithosphere, the next change the nitrogen will under go is it will beA used as a nutrient by plantsB fix by bacteria in the soilC absorbed into the atmosphere by lightning Based on source 4, what was the biggest change to Louisiana economy after the Civil War? The radioactive compound 14CO2 may be used as a tracer to study metabolism in plants. Suppose that a compound isolated from a plant exhibited 28, 32, 27, 39 and 40 counts of radioactive decays per minute. A blank sample used to measure the background counts of the radiation counter gave 28,21, 28 and 20 counts per minute. It appears that the isolated compound gives more counts than those from background. Can we be 95% confident that the compound is indeed radioactive? First aid care for someone who has fainted includes: A. Call 911 B. Do NOT give fluids C. Have the person lie flat for about fifteen minutes D. B and C Why is it necessary to follow social rules ? write briefly. Make up a sentence using the nonsense word nawion as an adjective. What impact did the Justinian Code have onThe Byzantine Empire?A. It built the Grand CathedralB. It constructed schoolsC. It was the law of the landD. It honored Hagia Sophia Please guys I have 10 maybe 20 minutes to get this finished What were social motivations for imperialism? What important crop helped Virginia to prosper? Pretest: The New Nation5Select the correct answer from each drop-down menu.According to the, all US citizens were allowed to bear and keep arms. Americans disagree whether theswere intended for individual self-defense or forResetNext What is the value of X? Bella is training for a marathon. She can run 19 miles in 150 minutes. How many miles can she run in 5 hours? The novel Long Way Down contains many different rulesboth stated and unstatedthat society must follow. Will says, In case you aint know / gunshots make everybody / deaf and blind especially / when they make somebody dead (19). What does he mean here? Why is this such an important rule to follow? Two moles of an ideal monatomic gas go through the cycle abc. For the complete cycle, 800 J of heat flows out of the gas. Process ab is at constant pressure, and process bc is at constant volume. States a and b have temperatures Ta = 200 K and Tb = 300 K.(a) Sketch the all possible pV-diagrarns for the cycle.(b) What is the work W for the process ca? Child labor continued even after the reforms of the 1910s because. please helppppppppppppp ASAP. please ensure to use step by step explanation. thanks.