You need to repair a broken fence in your yard. The hole in your fence is around 3 meters in length and for whatever reason, the store you go to has oddly specific width 20cm wood. Each plank of wood costs $16.20, how much will it cost to repair your fence?

Answer:

Many difficulties would arise if there was a lack of uniformity in the measurement of various weights and measures between business, industry, individuals and countries. The biggest implications for a lack of uniformity are in health and safety, equity and sustainability.

Explanation:

palike nlng po

Answer:

i) 60 W

ii) 100 W

Explanation:

In each case, the bulb that dissipates the most power is the bulb that glows brighter.  Power is voltage times current (P = VI).  Using Ohm's law, we can rewrite this as P = I²R or P = V²/R.

Bulbs are rated at a certain power for a certain voltage.  P = V²/R, so the bulb with the lower resistance will have the higher power rating.  Therefore, the 100 W bulb has a lower resistance than the 60 W bulb.

i) They are in series, so they have the same current.  P = I²R, so the bulb with the higher resistance will glow brighter.  That's the 60 W bulb.

ii) They are in parallel, so they have the same voltage.  P = V²/R, so the bulb with the lower resistance will glow brighter.  That's the 100 W bulb.

Answer:

The percentage error in quantity P is 19%.

Explanation:

It is given that,

A physical quantity P is related to four observables a, b and c as follows:

[tex]P=\dfrac{a^3b^2}{c^4}[/tex]

The percentage errors of measurements in a, b and c are 1%, 4% and 2% respectively.

We need to find the percentage error in quantity P. It is given by :

[tex]\dfrac{\Delta P}{P}\times 100=(3\times \dfrac{\Delta a}{a}+2\times \dfrac{\Delta b}{b}+4\times \dfrac{\Delta c}{c})\\\\=3\times 1+2\times 4+4\times 2\\\\\dfrac{\Delta P}{P}\times 100=19\%[/tex]

So, the percentage error in quantity P is 19%.

Answer:

gagaggagagagagooo

Explanation:

gagagagagagagagaoooo

Answer:

Explanation:

The velocity ratio of  a wheel and axle is the ratio of the radius (R) of the wheel to the radius (r) of the axle. It is expressed as;

VR = R/r

Since radius = diameter/2

VR = (D/2)/(d/2)

VR = D/d

D is the diameter of the wheel and 'd' is the diameter of the axle.

Given VR = 3 and d = 5cm

3 = D/5

D = 15 cm

If the diameter of the wheel is 15cm, the radius of the wheel will be 15/2 = 7.5cm.

b) Workdone by the load = Load * distance moved by load

Given load = 60kg

Distance moved by load = 2π*radius of axle

Distance moved by load  = 2π(0.025) = 0.157

workdone by load = 60* 0.157 = 9.42J

Effort = Workdone by load/distance moved by the wheel

Effort = 9.42/2π(0.075)

Effort = 9.42/0.471

Effort = 20kg

Hence the effort applied is 20kg

c) MA = Load/Effort

MA = 60/20

MA = 3

d) Efficiency = MA/VR * 100%

Efficiency = 3/3 * 100%

Efficiency = 100%

Explanation:

Assuming the suitcase is near the surface of the earth, g = 9.8 m/s².

F = ma

F = (20 kg) (9.8 m/s²)

F = 196 N

Answer:

Explanation:

Given parameters

initial velocity u = 4.9m/s

height of drop H = 100m

acceleration due to gravity g = -9.8m/s²(since the body is ascending i.e moving against gravity)

Required

time taken by the packet to reach the ground 't'

Using the equation of motion

S = ut+1/2gt²

0-100 = 4.9t+1/2(-9.8)t²

-100 = 4.9t-1/2(9.8)t²

-100 = 4.9t-4.9t²

4.9t-4.9t² +100 = 0

4.9t²-4.9t² -100 = 0

Multiplying through by 10

49t²-49t-1000 = 0

Using the general equation t = (-b±√b²-4ac)/2a

t = -(-49)±√(-49)²-4(49)(-1000)/2(49)

t = 49±√(2401+196000)/2(49)

t = 49±√(198401)/98

t = 49±√(198401)/98

t = 49±449.42/98

t = (49+449.42)/98

t = 494.42/98

t = 5.04secs

Hence, it took the packet 5.04secs to reach the ground

The final velocity is calculated using the formula v = u + at

v = u-gt

v = 4.9-(9.8)(5.04)

v = 4.9-49.392

v = -44.492m/s

This shows that the final velocity is 44.49m/s(moving downwards)

Answer:

(B)

Explanation:

the boy will fall away from the bus if the bus is moving.

6. Force

7 speed

8 distance

9 acceleration

Answer:

The pressure at the bottom of the river is less than that at the bottom of the lake.

Explanation:

From Bernoulli's equation, the pressure difference is given by

ΔP = ρgΔh + ρ(v₂² - v₁²)/2 where ρ = density of water, g = acceleration due to gravity, Δh = depth, v₁ = velocity at top, v₂ = velocity at bottom

For the lake, v₁ = v₂, since the velocity at the top and bottom are the same. So,

ΔP₁ = ρgΔh + ρ(v₁² - v₁²)/2 = ρgΔh + 0 = ρgΔh

P₂ - P₁ = ρgΔh

P₂ = P₁ + ρgΔh

For the river, v₁ < v₂, since the velocity at the top of the river is greater than at the bottom.

So,

ΔP₂ = ρgΔh + ρ(v₂² - v₁²)/2.

Since  v₁ < v₂, ρ(v₂² - v₁²)/2 will be negative,

So,

ΔP₂ = ρgΔh - ρ(v₂² - v₁²)/2.

Since ρ(v₂² - v₁²)/2 is negative, making ΔP less than that in the lake.

So, ΔP₂ = ΔP₁ -  ρ(v₂² - v₁²)/2.

ΔP₂ = P₃ - P₁

P₃ - P₁ = P₂ - P₁ -  ρ(v₂² - v₁²)/2.

P₃ = P₂ - ρ(v₂² - v₁²)/2.

where P₃ = pressure at bottom of the river and P₂ = pressure at bottom of the lake and P₁ = atmospheric pressure at top of river and lake respectively.

Since the factor ρ(v₂² - v₁²)/2 is removed from the pressure at the bottom of the lake, the pressure at the bottom of the river is therefore less than that at the bottom of the lake.

Lithium element contains one electron therefore valence electron will be one.  

The highest level of energy is due to valence electrons which are available to the atom.

The calcium has 2 valence electrons which has electrons with high energy.

These energy will be used by the electron during the chemical reaction, and they will either lose or gain valence electron.

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Answer:

calcium

Explanation:

2 electron

Answer:

449.38 J

Explanation:

ΔS = ΔQ/T

Where ΔS = entropy change

Q = quantity of heat

T = temperature

First reservoir :

T = –30°C = - 30 + 273 = 243K

Q = 400 J

Second reservoir :

T = 0°C = 273K

Q =?

To have same increase in entropy for both reservoirs :

Q/T of first reservoir = Q/T of second reservoir

400/243 = Q/273

243 * Q = 400 * 273

Q = (400 * 273) / 243

Q = 109,200 / 243

Q = 449.38271

Q = 449.38 J

Explanation:

Let 'F' be force acting perpendicularly, 'A' be the area and 'P' be the pressure exerted.

Then,

Pressure is directly proportional to the the force acting perpendicularly i.e.

P ∝ F ............. (i)

Pressure is inversely proportional to the area on which force acts i.e.

P ∝ 1/A ........... (ii)

Combining equations (i) and (ii),

P ∝ F/A

or, P = K × F/A [where K is a constant]

If F is 1N, A is 1m² and P is 1 N/m², then K is 1.

So, P = F/A proved...

Answer:

2660 m

Explanation:

Sum of the forces in the first 6.00 s:

∑F = ma

F − mg = ma

35.0 N − (0.800 kg) (10 m/s²) = (0.800 kg) a

a = 33.75 m/s²

The height it reaches during this time is:

Δy = v₀ t + ½ at²

Δy = (0 m/s) (6.00 s) + ½ (33.75 m/s²) (6.00 s)²

Δy = 607.5 m

The velocity it reaches is:

v = at + v₀

v = (33.75 m/s²) (6.00 s) + 0 m/s

v = 202.5 m/s

After the battery runs out, the drone is in free fall.  At the highest point, the velocity is 0.  The height at this point is:

v² = v₀² + 2aΔy

(0 m/s)² = (202.5 m/s)² + 2 (-10 m/s²) (h − 607.5)

h ≈ 2660 m

Explanation:

Given that,

Number of loops are 3

Length of slinky is 3.75 m

They time 20 oscillations in  6.73 s.

We need to find the wavelength of  the standing wave.

For 3 loops, [tex]L=\dfrac{3\lambda}{2}[/tex]

Here, [tex]\lambda[/tex] is the wavelength of the standing wave

So,

[tex]\lambda=\dfrac{2L}{3}\\\\\lambda=\dfrac{2\times 3.75}{3}\\\\\lambda=2.5\ m[/tex]

So, the wavelength of the standing wave is 2.5 m.

a) Her acceleration during the slide is -6.67 m/s².

b) She slides 1.03 seconds until she stops.

a) We can find her acceleration during the slide with Newton's second law:

[tex] F = ma [/tex]                        

Where:

F: is the force    

m: is the mass = 92.45 kg

a: is the acceleration =?

The force acting on the baseball player is equal to the friction force ([tex]F_{\mu}[/tex]), and it is negative because it is in the opposite direction to the motion:

[tex] -\mu N = ma [/tex]

[tex] -\mu mg = ma [/tex]

[tex] a = -\mu g [/tex]

Where:

N: is the normal force = mg

μ: is the coefficient of kinetic firction = 0.68

g: is the acceleration due to gravity = 9.81 m/s²

Hence, her acceleration during the slide is:

[tex] a = -0.68*9.81 m/s^{2} = -6.67 m/s^{2} [/tex]

b) We can calculate how long does she slide until she stops with the following kinematic equation:

[tex] v_{f} = v_{0} + at [/tex]

Where:

[tex] v_{f} [/tex]: is the final speed = 0 (when she stops)

[tex] v_{0} [/tex]: is the initial speed = 6.87 m/s

t: is the time =?

Then, the time is:

[tex] t = -\frac{v_{0}}{a} = -\frac{6.87 m/s}{-6.67 m/s^{2}} = 1.03 s [/tex]

You can learn more about Newton's second law here: https://brainly.com/question/19860811?referrer=searchResults

I hope it helps you!

Answer:

Concave mirror makes someone looking at it look dwarf or short, while convex mirror stretches the person making the person look weird.

In free fall

[tex]\boxed{\sf s=-\dfrac{1}{2}gt^2}[/tex]

[tex]\\ \sf\longmapsto s=-\dfrac{1}{2}\times 9.8(1)^2[/tex]

[tex]\\ \sf\longmapsto s=-4.9(1)[/tex]

[tex]\\ \sf\longmapsto s=-4.9m[/tex]

[tex]\\ \sf\longmapsto s=4.9m[/tex]

Answer:

when you are paddling the push carry on when you paddle the hard put on the push.

Answer:

Because of inertia

Explanation:

As stated in Newton first law "An object at rest will stay at rest, an object in motion will stay in motion unless it is acted upon by a force."

For an example:

If you have a drink without a lid in a car and a car suddently the car stop, u will automatically try to catch the drink preventing it from spilling. This is because that the drink that was in motion with the car want to stay in motion, but when the car stop, the drink still wanna be in motion, that's why it will be flying off and spill if u don't catch it.

Back to the question:

if a bicyccle is in motion, it will wants to be in motion untill a force act upon it, let's say a bump or fricition.

hope this help. give me the brainliest if u can.

Answer:

When we have irregular objects, it may become very hard to calculate the volume of the object, as we actually can not use any simple equation to find it.

The mass is less tricky, just find a scale and wheight it, now we know the mass of the irregular object.

One way to measure the volume of the object is using water... how we do it?

Get some recipient with water, measure the height of the water.

Introduce your object into the water and totally submerge it, now the level of the water will rise. This is because as you introduce the object under the water, you are displacing up a given volume of water that has the same volume as the irregular object.

Now that you know the height of the water before and after you put your object, you can easily calculate the volume of water displaced, and that will be the volume of the object (the tricky part may be totally submerging the object if, for example, is wood and it floats, here you can use a thin wire to push it down but it will affect a little bit the measures.)

Answer:

Which best describes what happens if two waves meet and build on each other?

destructive interference

reflection

absorption

Explanation:

When two waves meet in phase they will overlap together and form a constructive interference. The resultant amplitude of the waves will be greater than that of individual waves.

A wave of greater, lower, or the same amplitude is created when two waves merge through interference by combining their displacements at all points in space and time.

The interaction of waves that are coherent or correlated with one another, either because they originate from the same source or because their frequencies are similar or almost identical, leads to both constructive and destructive interference.

All sorts of waves, including light, radio, acoustic, surface water waves, gravity waves, and matter waves, can exhibit interference effects. In constructive interference, the waves are in single phase forms a resultant wave with higher amplitude.

When waves from out of phase meets, the resultant wave will have an amplitude less than the individual amplitudes. Here, the waves are meet in phase and build on each is constructive interference.

Find more on interferences :

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Answer:

B.

Explanation:

as there is a '-' sign before the magnification value, it forms a real image.

so the last two options get cancelled.

as the value of magnification is 0.87 ie. lesser than 1, we can say that the image is smaller.

The type of image is formed by a lens if m = -0.87 would be smaller than the object and the object is real

A lens is a transmissive optical tool that employs refraction to focus or disperse a light beam. The power of the lens is expressed in the dioptre which is the reciprocal of the focal length of the lens.

The image formation through the lens is calculated with the help of the lens formula given as follows

1/f = 1/v - 1/u

where f is the focal length of the lens

u is the distance of the object from the lens

v is the distance of the image formed from the

magnification (m) = size of image /size of the object

As given in the problem image is formed by a lens if m = -0.87

Thus, the negative sign represents that the image formed by the object is real, and the magnitude of the magnification is less than 1 this represents that size of the image is smaller than the size of the object.

Learn more about the lens from here

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Answer:

6097 = x

Explanation:

x = VT + at²/2

x= 2.7 * 35 + 9.8 * (35)²/2

x=6097

Ramsar has the highest level of natural radiation in the world.

Hot springs located in the Arkaroola Wilderness Sanctuary in Southern Australia are also credited with higher than normal radiation levels, due to spring water coming in contact with rocks rich in uranium and radon.

Answer:

Action and reaction are equal but act in opposite directions

Answer:

Newton’s third law of motion states that “ for every action there is always an equal and opposite reaction.”

Explanation:

If body A exerts a force on body B, then body B will exert an equal and opposite force on body A. It is also called action reaction force. They have equal magnitude but are opposite in direction.

Explanation:

The area under a displacement vs time graph is the absement.

Answer:

Explanation:

Energy of gamma ray = 2.2233 MeV

Let mass of neutron be n  amu  

mass defect of deuteron = 2.013553212 - ( 1.007 276 467 + n ) u .

in terms of energy this mass defect will be equal to energy of gamma ray

1 amu = 931 MeV

931 [ 2.013553212 - ( 1.007 276 467 + n ) ] =  2.2233

( 1.007 276 467 + n ) -  2.013553212  = .00238807733

n = 1.008664822 amu

so mass of neutron = 1.008664822 amu

Answer:

[tex]t = 0.75 \ hr = 0.75 *60 = 45 \ minutes[/tex]

Explanation:

From the question we are told that

   The  hydraulic conductivity is  [tex]Ks = 10\ mm/hr[/tex]

    The  effective matrix potential [tex]Ns = 20 \ mm[/tex]

    The  intensity of  rainfall is  [tex]I = 30 \ mm/hr[/tex]

    The runoff rate [tex]R = 15 \ mm/hr[/tex]

Generally the run off rate is mathematically represented as  

      [tex]R = (I - Ks) t[/tex]

Here t is the amount of runoff generated

=>   [tex]15 = (30 - 10) t[/tex]

=>  [tex]t = 0.75 \ hr[/tex]

converting to minutes

    [tex]t = 0.75 \ hr = 0.75 *60 = 45 \ minutes[/tex]

Answer:

0 degrees Celsius is 273 degrees Kelvin. As both pressure and volume are proportional to absolute temperature, in order to double both you would need to quadruple the temperature. I.e. 273 X 4 = 1092 Kelvin = 819 Celsius

Explanation: