pls help i’m begging you

Hardness, color , and luster.

But since you can pick one, I would say hardness

Answer:

Power = 2.45Kw or 2450 Watts.

Explanation:

Given the following data;

Mass, m = 250kg

Height, h = 2m

Time, t = 2secs

We know that acceleration due to gravity, g is equal to 9.8m/s²

Power can be defined as the energy required to do work per unit time.

Mathematically, it is given by the formula;

[tex] Power = \frac {Energy}{time} [/tex]

But Energy = mgh

Substituting into the equation, we have

[tex] Power = \frac {mgh}{time} [/tex]

[tex] Power = \frac {250*9.8*2}{2} [/tex]

[tex] Power = \frac {4900}{2} [/tex]

Power = 2450 Watts

To convert to kilowatt (Kw), we would divide by 1000

Power = 2450/1000

Power = 2.45Kw.

Therefore, the average power output of the weightlifter is 2.45 Kilowatts.

The average power output of the weight lifter who can lift the given mass is 2450 Watts.

Given the data in the question;

Power is the amount of energy transferred per unit time. It is expressed as:

[tex]P = \frac{W}{\delta t}[/tex]

Where W is work done and t is elapsed time.

So, we find the work done

Work done = Force × Displacement

Since Force = Weight = m × g

Where g is acceleration due to gravity ( [tex]9.8m/s^2[/tex] )

Hence

[tex]Work\ done = mg * d\\\\Work\ done = 250kg\ *\ 9.8m/s^2\ *\ 2.0m\\\\Work\ done = 4900kg.m^2/s^2[/tex]

We substitute our value into the previous equation

[tex]P = \frac{Work\ done}{\delta t}\\\\P = \frac{4900kg.m^2/s^2}{2.0s} \\\\P = 2450kg.m^2/s^3\\\\P = 2450J/s\\\\P = 2450W[/tex]

Therefore, the average power output of the weight lifter who can lift the given mass is 2450 Watts.

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Answer: negatively charged particles move from one point to another

Explanation:

In electricity, negatively charged particles move from one point to another.​ The correct option is D.

Electric current is what causes electricity to exist and move. We can transmit energy using electricity so that we can carry out easy tasks.

The movement of electrons through conductors like copper wires is its most well-known manifestation. Electrical energy is commonly referred to as "electricity."

The flow of electrical power, commonly referred to as a charge, is the source of the energy type known as electricity.

Our homes, lights, and electrical devices are all powered by electricity. Resources including coal, energy, natural gas, and oil are used to generate power.

Particles that are negatively charged in electricity travel from one location to another.

Thus, the correct option is D.

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Answer:

F =mg

200= m ×10

200/10 =m

20kg= m

Answer:

The correct answer is b.

Answer:

Explanation:

From the given information:

We can estimate the  cross-sectional area of the pipe by using the formula:

[tex]A_c = \dfrac{\pi}{4} D^2[/tex]

[tex]A_c = \dfrac{\pi}{4} (6 \times 10^{-2} \ m)^2[/tex]

[tex]A_c = 0.0028274 \ m^2[/tex]

To find the average velocity of the water flowing through the pipe by using the formula;

[tex]V = \dfrac{\mathtt{V}}{A_c}[/tex]

[tex]V = \dfrac{10 \times 10^{-3} \ m^3/s}{0.0028274}[/tex]

[tex]V = 3.537 \ m/s[/tex]

However, the Reynolds number can be determined by using the equation

[tex]Re= \dfrac{\rho \times V \times D}{\mu}[/tex]

[tex]Re= \dfrac{(999.1 \ kg/m^3) \times (3.537 \ m/s) \times (6 \times 10^{-3} \ m)}{1.138 \times 10^{-3} \ kg/m.s}[/tex]

Re = 18631.7225

From above, Re> 4000, thus, the flow will be turbulent.

By using Colebrook's equation in a turbulent flow; we have the following expression for Colebrook's equation:

[tex]\dfrac{1}{\sqrt{f}}= -2.0 \ log \bigg ( \dfrac{\epsilon/D_h}{3.7}+ \dfrac{2.51}{Re \sqrt{f}} \bigg )[/tex]

where;

[tex]f[/tex] = frictional force = ???

[tex]\epsilon[/tex] = roughness of steel= 0.002 mm

Replacing our values into the above equation, we have:

[tex]\dfrac{1}{\sqrt{f}}= -2.0 \ log \bigg ( \dfrac{ 2\times 10^{-6 \ m }/6 \times 10^{2 }\ m}{3.7}+ \dfrac{2.51}{18631.7225 \sqrt{f}} \bigg )[/tex]

By solving the above equation for f; we get

f = 0.026409

The pressure drop in flow;

[tex]\Delta P_L = f \dfrac{L}{D} \dfrac{\rho V^2}{2}[/tex]

[tex]=0.026409(\dfrac{29}{0.06})(\dfrac{999.1*3.537^2}{2})[/tex]

= 79771.50524 Pa

= 79.772 kPa

The pressure drop = 79.772 kPa

The head loss in the pipe:

[tex]h_L = \dfrac{\Delta P_L}{\rho g}[/tex]

= [tex]\dfrac{79771.50524 }{999.1 * 9.81}[/tex]

= 8.14 m

The power input

[tex]W_{pump} = V\Delta P_L[/tex]

=  10 * 10^{-3} * 79771.50524

= 797.72 W

Answer:

sorry about the other person but its b

Explanation:

Answer:

this is the correct answer

Explanation:

Answer:

When we increase the applied force (push harder), the frictional force will also increase until it reaches a maximum value. When the applied force is larger than the maximum force of static friction the object will move. ... For kinetic friction the value remains the same regardless of the magnitude of the applied force.

Answer:

attract each other

Explanation:

attract each other, opposite charges attract each other, similar charges repel.

Answer: time=4 hours

Explanation:

formula:

speed = [tex]\frac{distance}{time}[/tex]

time = [tex]\frac{distance}{speed}[/tex]

time= x

speed = 120km/hr

distance = 480 km

x = [tex]\frac{480 km}{120km/hr\\}[/tex]

=[tex]\frac{48km*hr}{12km}[/tex]

cut the zeros

and remove the signs

then

[tex]\frac{48}{12}[/tex] = 4

therefore, time taken to deliver the shipment by trucker is 4 hours

Answer:

kinetic & potential

Explanation: whats the other 2 tho?

Answer:

A car

Explanation:

A car can travel 100 m in 5 seconds

Hope this helps!

Answer:

W = 600 N

Explanation:

The mechanical advantage of any machine is the ratio of the load or weight to the effort applied. Hence, the general formula for mechanical advantage is as follows:

M.A = W/P

where,

M.A =Mechanical Advantage of Hammer = 10

W = Maximum force that could be generated = ?

P = Force created by me = 60 N

Therefore,

10 = W/60 N

W = 10*60 N

W = 600 N

Answer:

b

Explanation:

a=v2/r

=0.89^2/2.8

=0.2828...

=0.28

The centripetal acceleration of the child sitting on a merry-go-round 2.8 m from the center will be 0.283 m/s².

Centripetal acceleration is the constant change in velocity necessary for an object to maintain a circular path. We can write the formula for centripetal acceleration as -

a[C] = v[T]²/r

where -

v[T] is tangential velocity

r is radius

Given is a child is sitting on a merry-go-round 2.8 m from the center and the tangential velocity of the ride is 0.89 m/s.

We can write -

Radius [r] = 2.8 m

Tangential velocity = v[T] = 0.89 m/s.

Using the formula for centripetal acceleration -

a[C] = v[T]²/r

a[C] = (0.89 x 0.89)/2.8

a[C] = 0.283 m/s²

Therefore, the centripetal acceleration of the child sitting on a merry-go-round 2.8 m from the center will be 0.283 m/s².

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Answer:

Wavelength!

Explanation:

At least I think? Or wavelength might be crest to crest! Sorry if I'm incorrect. Let me know how I did!

Answer:

I would think the first and the third answer

Answer:

i would say 3rd cause other may slightly effect

Answer:

0.54m

Explanation:

Step one:

given data

length of seesaw= 3m

mass of man m1= 85kg

weight = mg

W1= 85*10= 850N

mass of daughter m2= 35kg

W2= 35*10= 350N

distance from the center= (1.5-0.2)= 1.3m

Step two:

we know that the sum of clockwise moment equals the anticlockwise moment

let the distance the must sit to balance the system be x

taking moment about the center of the system

350*1.3=850*x

455=850x

divide both sides by  850

x=455/850

x=0.54

Hence the man must sit 0.54m from the right to balance the system

Answer:

The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed

Explanation:

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Answer:

C

YExplanation:

Answer:

[tex]a=0.611\ m/s^2[/tex]

Explanation:

Given that,

Mass of a refrigerator, m = 90.01 kg

She is able to slide the refrigerator across the floor with 55  N of force.

We need to find the acceleration of the refrigerator.

Let it is a. Using second law of motion:

F = ma

[tex]a=\dfrac{F}{m}\\\\a=\dfrac{55\ N}{90.01\ kg}\\\\a=0.611\ m/s^2[/tex]

So, its acceleration is [tex]0.611\ m/s^2[/tex].

Answer:

True

Explanation:

Answer:

Q = 73325 J or 73.325 KJ

Explanation:

According to specific heat capacity, 73,325 J of energy must be absorbed by water with a mass of 0.5 kg in order to raise the temperature from 30°C to 65°C.

Specific heat capacity is defined as the amount of energy required to raise the temperature of one gram of substance by one degree Celsius. It has units of calories or joules per gram per degree Celsius.

It varies with temperature and is different for each state of matter. Water in the liquid form has the highest specific heat capacity among all common substances .Specific heat capacity of a substance is infinite as it undergoes phase transition ,it is highest for gases and can rise if the gas is allowed to expand.

It is given by the formula ,

Q=mcΔT

In the given example, substitution in above formula gives,Q=0.5×4190×35=73,325 J.

Thus, 73,325 joules of energy must be absorbed by water with a mass of 0.5 kg .

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negative charge come from the gain of electron

Answer:

An electrical charge is created when electrons are transferred too or removed from an object. Because electrons have a negative charge, when they are added to an object, it becomes negatively charged. When electrons are removed from an object, it becomes positively charged.

From G00gle

Explanation:

Answer:

V = -39.2m/s

Explanation:

Given the following data

Time, t = 4secs

Since the rock is falling, we know that the initial velocity = 0

Acceleration due to gravity = 9.8m/s²

To find the final velocity, we would use the first equation of motion

V = U + at

Substituting into the equation, we have

V = 0 + (-9.8*4)

V = -39.2m/s

Complete Question

The complete question is shown on the first uploaded image

Answer:

The components of reaction at the fixed support are  

    [tex]A_{(x)} = 400 \ N[/tex] ,  [tex]A_{(y)} = -500 \ N[/tex] ,  [tex]A_{(z)} = 600 \ N[/tex] ,  [tex]M_x = 1225 \ N\cdot m[/tex] , [tex]M_y = 750 \ N\cdot m[/tex] ,  [tex]M_z = 0 \ N\cdot m[/tex]

Explanation:

Looking at  the diagram uploaded we see that there are two  forces acting along the x-axis on the fixed support    

   These force are  400 N  and  [tex]A_{(x)}[/tex] [ i.e the reactive force of  400 N  ]

Hence the sum of forces along the x axis is mathematically represented as

        [tex]A_{(x)} - 400 = 0[/tex]

=>     [tex]A_{(x)} = 400 \ N[/tex]

Looking at  the diagram uploaded we see that there are two  forces acting along the y-axis on the fixed support  

   These force are  500 N  and  [tex]A_{(y)}[/tex] [ i.e the force acting along the same direction with 500 N   ]

Hence the sum of forces along the x axis is mathematically represented as

        [tex]A_{(y)} + 500 = 0[/tex]

=>     [tex]A_{(y)} = -500 \ N[/tex]

Looking at  the diagram uploaded we see that there are two  forces acting along the z-axis on the fixed support  

       These force are  600 N  and  [tex]A_{(z)}[/tex] [ i.e the reactive force of  600 N  ]

Hence the sum of forces along the x axis is mathematically represented as

        [tex]A_{(z)} - 600 = 0[/tex]

=>     [tex]A_{(z)} = 600 \ N[/tex]

Generally taking moment about A along the x-axis we have that

    [tex]\sum M_x = M_x - 500 (0.75 + 0.5) + 600 ( 1 ) = 0[/tex]

=>   [tex]M_x = 1225 \ N\cdot m[/tex]

Generally taking moment about A along the y-axis we have that

    [tex]\sum M_y = M_y - 400 (0.75 ) + 600 ( 0.75 ) = 0[/tex]

=>   [tex]M_y = 750 \ N\cdot m[/tex]

Generally taking moment about A along the z-axis we have that

    [tex]\sum M_z = M_z = 0[/tex]

=>   [tex]M_z = 0 \ N\cdot m[/tex]

Answer:

Exothermic

Explanation:

A burning match represents an exothermic reaction. The chemicals release energy in the form of heat and light as the reaction progresses.

Answer:

A burning match represents an exothermic reaction. The chemicals release energy in the form of heat and light as the reaction progresses.

Explanation:

Its the sample response.

Answer:

because of its mass. Momentum is directly propotional to the mass of a body

Answer:

Mass

Explanation:

A tennis ball has a mass of around 57 grams and a cricket ball has a mass of around 156 grams. It's much easier to catch a fast moving tennis ball because it is lighter than a cricket ball. Hope this helps x