A man holds a rectangular card in front of and parallel to a plane mirror. In order for him to see the entire image of the card, what is the least mirror area needed ?

Answer:

Explanation:

The most important thing to remember about parabolic motion in physics is that when an object reaches its max height, the velocity right there at the highest point is 0. Use this one-dimensional motion equation to solve this problem:

v = v₀ + at and filling in:

0 = v₀ + (-9.8)(4.0) **I put in 4.0 for time so we have more than just 1 sig fig here**

0 = v₀ - 39 and

-v₀ = -39 so

v₀ = 39 m/s

Answer:

water cycle show the continuous movement of water with in the earth and atmosphere

Explanation:

Hope this helps :)

The water cycle is the process through which water evaporates from the earth's surface, rises into the atmosphere, cools and condenses into rain or snow in clouds, and then falls back to the surface as precipitation. Water that falls on land gathers in rivers and lakes, soil, and porous rock strata, and much of it goes back into the seas to evaporate. Water flows in and out of the system.

Answer:

The main difference between friction and viscosity is that friction is used to refer to forces that resist relative motion, in general, whereas viscosity refers specifically to resistive forces that occur between layers of a fluid when fluids attempt to flow.

Explanation:

Answer:

Viscosity

Viscosity is defined as a measure of the resistance of a fluid, which is being deformed by either shear stress or tensile stress. In more common words, viscosity is the “internal friction” of a fluid. It’s also referred as the thickness of a fluid. Viscosity is simply the friction between two layers of a fluid when the two layers move relative to each other. Sir Isaac Newton was a pioneer in fluid mechanics. He postulated that, for a Newtonian fluid, the shear stress between layers is proportional to the velocity gradient in the direction perpendicular to the layers. The proportional constant (proportionality factor) used here is the viscosity of the fluid. The viscosity is usually denoted by the Greek letter “µ”. Viscosity of a fluid can be measured using Viscometers and Rheometers. The units of viscosity are Pascal-seconds (or Nm-2s). The cgs system uses the unit “poise”, named after Jean Louis Marie Poiseuille, to measure viscosity. Viscosity of a fluid can also be measured by several experiments. The viscosity of a fluid depends on the temperature. The viscosity decreases as the temperature is increased.

τ = μ (∂u / ∂y)

Viscosity equations and models are very complex for non-Newtonian fluids. It can be clearly seen that viscosity always acts in a direction, to oppose the flow of the liquid. Viscous forces are distributed throughout the volume of the liquid in a given dynamic condition.

Friction

Friction is probably the most common resistive force we experience every day. Friction is caused by the contact of two rough surfaces. Friction has five modes; dry friction that occurs between two solid bodies, fluid friction, which is also known as viscosity, lubricated friction, where two solids are separated by a liquid layer, skin friction, which opposes a moving solid in a liquid, and internal friction that causes the internal components of a solid to make friction. However, the term “friction” is most commonly used in place of dry friction. This is caused by the rough microscopic cavities on each of the surfaces fitting each other and refusing to move. The dry friction between two surfaces depends on the friction coefficient and the reactive force normal to the plane acting on the object. The maximum static friction between two surfaces is just a bit higher than the dynamic friction.

Explanation:

PLS MARK ME BRAINLIEST

Answer:

Current in the circuit(I) = 0.5 ampere

Explanation:

Given:

Number of resistors = 2 (10 ohm each)

Series of resistors

EMF = 10 volt

Find:

Current in the circuit(I)

Computation:

Total resistance in series = R1 + R2

Total resistance in series = 10 + 10

Total resistance in series = 20 ohm

Current in the circuit(I) = EMF / Total resistance in series

Current in the circuit(I) = 10 / 20

Current in the circuit(I) = 0.5 ampere

Explanation:

first find the volume of room --->

[tex]v \: = 10 \times 12 \times (400 \times {10}^{ - 2} ) \times = 480 \: {m}^{3} [/tex]

then find the mass

[tex]mass \: = \: density \: \times \: volume \: = 480 \times 1.26 = 604.8 \: kg[/tex]

Answer:

A

Explanation:

An object reaches top velocity for its mass, then it falls at that same speed until a force acts on it

Answer:

Explanation:

a. GPE = mgh which is mass times gravity times height. For us, this is

GPE = 260(9.8)(5.0) so

GPE = 13000 J rounded to 2 sig fig's

b. is a little bit more involved, since we are on an incline. The formula for this is usually

[tex]wsin\theta-f=ma[/tex] where f is the pull of friction on the object. But we have no friction here, so f = 0. That means that we need to find the angle of inclination using right triangle trig. We have the height as 5.0 m and we have the length of the ramp as 13 m, so we an find the angle using the inverse sin button on our calculator.

[tex]sin\theta=\frac{5.0}{13}[/tex] so

[tex]\theta=23[/tex] degrees, rounded to 2 sig fig's as needed.

The formula to find Force is F = ma, which means we need the acceleration found in the equation

[tex]wsin\theta=ma[/tex]. Filling in:

weight = 9.8(260) = 2500 N so

2500sin23 = 260a and

a = 3.8 m/sec². Now we can find force:

F = 260(3.8) so

F = 990N

c. To life the piano straight up, we just need to overcome the pull of gravity along with the mass of the piano and the angle at which it is sitting. That has a formula of

Normal force = weight = wcosθ so

Normal force = 2500cos23 and

Normal force = 2300N

3 is false 2 is true and the rest true

Answer;

True, False, False, True, True

Answer:

200 N

Explanation:

Since Young's modulus for the metal, E = σ/ε where σ = stress = F/A where F = force on metal and A = cross-sectional area, and ε = strain = e/L where e = extension of metal = change in length and L = length of metal wire.

So,  E = σ/ε = FL/eA

Now, since at break extension = e.

So making e subject of the formula, we have

e = FL/EA = FL/Eπr² where r = radius of metal wire

Now, when the radius and length are doubled, we have our extension as e' = F'L'/Eπr'² where F' = new force on metal wire, L' = new length = 2L and r' = new radius = 2r

So, e' = F'(2L)/Eπ(2r)²

e' = 2F'L/4Eπr²

e' = F'L/2Eπr²

Since at breakage, both extensions are the same, e = e'

So,  FL/Eπr² = F'L/2Eπr²

F = F'/2

F' = 2F

Since F = 100 N,

F' = 2 × 100 N = 200 N

So, If the radius and length of the wire were both doubled then it would break when the tension reached 200 Newtons.

Answer:

Explanation:

I'll try to answer this is clearly as possible without talking in circles. If an object is launched into projectile motion, something was behind it, pushing it forward. Once this launching was done, the launching mechanism was no longer important to the object and the object is free to keep moving forward at that same velocity forever...if that was the only thing at play here. But, because of air resistance and GRAVITY, the object is pulled down and eventually hits the ground. In other words, if there was no such thing as gravity, an object would continue to move forever in the diretion and at the speed at which it was launched.

Answer:

As an object moves faster, its mass increases. ... Because masses approach infinity with increasing speed, it is impossible to accelerate a material object to (or past) the speed of light. To do so would require an infinite force.

Answer:

6.58×10⁶ F

Explanation:

Applying,

Q = CV..................... Equation 1

Where Q = charge of the capacitor, C = Capacitance of the capacitor, V = Volatage

Make C the subject of the equation

C = Q/V................. Equation 2

From the question,

Given: Q = 7.9×10⁷ C, V = 12.0 V

Susbtitute these values into equation 2

C = 7.9×10⁷/12

C = 6.58×10⁶ F

Answer:

Based on what we have learned so far, in what ways have the experiences of Asian-Canadians stayed the same over time? Why do you think these similarities exist? Please give specific examples to support your ideas.

Explanation:

Answer:

Disconnections and discrepancies 

between school-based norms and values and those of 

some pupils, especially those from 

nondominant cultures, are referred to 

as cultural discontinuity.

☆-----------------------------☆

☆Hope it helps...

☆Have a great day!!!

Answer:

According to online, it shows that lightning can be traveling at 186,000 miles in only one second!

Hope it was helpful

Answer:

Explanation:

The formula for this is

[tex]n_1sin\theta_1=n_2sin\theta_2[/tex] where the index of refraction of air is 1.00. Filling in and solving for n2:

1.00sin(25) = n₂sin(13) and

1.00(.423) = n₂(.225) and

[tex]\frac{1.00(.423)}{.225}=n_2[/tex] so

[tex]n_2=1.88[/tex], choice D.

Answer:

all I know is C

are there more questions? anyone?

-KARL IS STOOPID

Explanation:

use the formula

v= u+ at

v is final velocity , u is initial velocity , a is acceleration and t is time

put the values

20 = 0+ a×5

a = 4 m/s²

Answer:

Initial velocity(u)=0

Final velocity(v) =20 meters/ second

Time(t)=5

Acceleration (a)=?

a=v-u/t

a=20-0/5

a=20/5

a=4meters/second

Answer:

B. The medium increases in temperature while remaining in the same phase

Explanation:

Good luck on all your tests and Exams!

The sound wave will increase when the medium increases in temperature while remaining in the same phase.

Sound waves are composed of compressions and rare factions. Sound is a mechanical wave hence it moves by the vibration of air particles.

As such, the sound wave will increase when the medium increases in temperature while remaining in the same phase.

Learn more about sound waves:https://brainly.com/question/11797560

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Answer:

Final volume, V2 = 24.62 L

Explanation:

Given the following data;

Initial volume = 40 L

Initial pressure = 80 Pa

Final pressure = 130 Pa

To find the final volume V2, we would use Boyles' law.

Boyles states that when the temperature of an ideal gas is kept constant, the pressure of the gas is inversely proportional to the volume occupied by the gas.

Mathematically, Boyles law is given by;

[tex] PV = K[/tex]

[tex] P_{1}V_{1} = P_{2}V_{2} [/tex]

Substituting into the equation, we have;

[tex] 80 * 40 = 130V_{2} [/tex]

[tex] 3200 = 130V_{2} [/tex]

[tex] V_{2} = \frac {3200}{130}[/tex]

[tex] V_{2} = 24.62 [/tex]

Final volume, V2 = 24.62 Liters

Answer:

2 m/s

Explanation:

Applying,

The law of conservation of momentum

Total momentum before collision = Total momentum after collision

mu+m'u' = V(m+m')............... Equation 1

Where m = mass of the first freight car, m' = mass of the second freight car, u = initial velocity of the first freight car, u' = initial velocity of the second freight car, V = final combined velocity/ speed.

make V the subject of the equation

V = (mu+m'u')/(m+m')........... Equation 2

From the question,

Given: m = 1234 kg, m' = 2468 kg, u = 6 m/s, u' = 0 m/s (at rest)

Substitute these values into equation 2

V = [(1234×6)+(2468×0)]/(1234+2468)

V = 7404/3702

V = 2 m/s

Answer:

Gravitational POTENTIAL ENERGY is greatest at the highest point of a roller coaster.

Explanation:

hope this helps

have a great day/night :)

Action-reaction forces are equal and opposite forces that act on different objects, so they don't cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward.

Hope this helps =)

opaque glass does not allow light to pass through it.

Answer:

Energy

Explanation:

Answer:

E) 147 V

Explanation:

Ra+Rb+Rc = 14.0

V = IR

V = (10.5)(14.0)

V = 147 V

The potential difference across the source will be c)12V

Ohm's law states that  the current through a conductor between two points is directly proportional to the voltage across the two points .

since , R(A) , R(B) AND R(C) are in parallel combination , hence  equivalent

resistance of the circuit will be

1/R = 1/R(A) + 1/ R(B) + 1/ R(C)

1/R= 1/2 + 1/4 +1/8

1/R = 7/8

R = 8/7 ohm

from ohm's law

Voltage = current * resistance

V( source ) = current (in circuit ) * R (equivalent resistance)

V = 10.5 * (8/7)

V = 12 V

The potential difference across the source will be c) 12V

learn more about ohm's law :

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Answer:

D. Electric Charges