Marks: 1
What is the power of a light that uses 300 joules of energy in 60
seconds?
18,000 W
50 W
5 W
0.2 W

Answer:

(a)  209 Watt

(b) 4482.8 seconds

Explanation:

(a) P = 50×4.18

Where P = rate of heat loss in watt

    P = 209 Watt

Applying,

Q = cm(t₁-t₂)................ Equation 1

Where Q = amount of heat given off, c = specific heat capacity capacity of human, m = mass of the person, t₁ and t₂ = initial and final temperature.

From the question,

Given: m = 90 kg, t₁ = 40°C, t₂ = 37°C

Constant: c = 3470 J/kg.K

Substtut these values into equation 1

Q = 90×3470(40-37)

Q = 936900 J

But,

P = Q/t.............. Equation 2

Where t = time

t = Q/P............ Equation 3

Given: P = 209 Watt, Q = 936900

Substitute into equation 3

t = 936900/209

t = 4482.8 seconds

Answer:

Electric field at A = 9.28 x 10¹² N/C

Explanation:

Given:

K = 8.99 x 10¹² N/C

Missing information:

Length = 11 cm = 11 x 10⁻² m

q = 12.5 C

Find:

Electric field at A

Computation:

Electric field = Kq / r²

Electric field at A = [(8.99 x 10¹²)(12.5)] / [11 x 10⁻²]²

Electric field at A = 9.28 x 10¹² N/C

Answer:

148.5 N

Explanation:

Given that,

The mass of a bungee jumper, m = 55 kg

The downward acceleration, a = 7.1 m/s²

We need to find the net force acting on the jumper. As it is moving in downward direction, net force is :

T = m(g-a)

Put all the values,

T = 55(9.8 - 7.1)

= 148.5 N

So, the force exerted on the bungee cord is 148.5  N.

Answer:

The downward force is 148.5 N.

Explanation:

mass, m = 55 kg

downwards acceleration, a = 7.1 m/s^2

Let the force is F.

According to the newton's second law

m g - F = m a

F = m (g - a)

F = 55 (9.8 - 7.1)

F = 148.5 N

Answer:

The smallest and largest areas could be 6400 m and 7500 m, respectively.

Explanation:

The area of a rectangle is given by:

[tex] A = l*w [/tex]

Where:

l: is the length = 100 m

w: is the width

We can calculate the smallest area with the lower value of the width.

[tex] A_{s} = 100 m*64 m = 6400 m^{2} [/tex]                            

And the largest area is:

[tex] A_{l} = 100 m*75 m = 7500 m^{2} [/tex]  

Therefore, the smallest and largest areas could be 6400 m and 7500 m, respectively.            

I hope it helps you!                        

Answer:

the largest areas that the field could be is [tex]A_l[/tex]=7587.75 m

the smallest areas that the field could be is [tex]A_s[/tex]=6318.25 m

Explanation:

to the find the largest and the smallest area of the field measurement error is to be considered.

we have to find the greatest possible error, since the measurement was made nearest whole mile, the greatest possible error is half of 1 mile and that is 0.5m.

therefore to find the largest possible area we add the error in the mix of the formular for finding the perimeter with the largest width as shown below:

[tex]A_l[/tex]= (L+0.5)(W+0.5)

(100+0.5)(75+0.5) = (100.5)(75.5) = 7587.75 m

To find the smallest length we will have to subtract instead of adding the error factor value of 0.5 as shown below:

[tex]A_s[/tex]= (L-0.5)(W-0.5)

(100-0.5)(64-0.5) = (99.5)(63.5) = 6318.25 m

Answer:

a

Explanation:

because the electric field doesn't effect the conductor and its goes into storage for later

Answer:

Explanation:

The formula is

[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] and filling in:

[tex]F_g=\frac{(6.67*10^{11})(400)(800)}{(45^2)}[/tex] and multiply and divide all that out to get

[tex]F_g=1.1*10^{-8}[/tex]  It should really only be 1 significant digit since 400 and 800 both have only 1 significant digit, but I used 2. It should be

[tex]F_g=[/tex] 1 × 10⁻⁸ N

Answer:

The electric field is 9.3 x 10^12 N/C and the direction is away from the charge.

Explanation:

charge, Q = 12.5 C

distance, d = 11 cm = 0.11 m

Let the electric field is E.

[tex]E =\frac{K Q}{d^2}\\\\E = \frac{9\times 10^9\times 12.5}{0.11\times 0.11}\\\\E = 9.3\times 10^{12} N/C[/tex]

The direction of electric filed is away from the charge.

Answer:

[tex]F_r=0.132:0.25[/tex]

Explanation:

From the question we are told that:

[tex]M_1=M*\frac{1}{6.334}[/tex]

Therefore

[tex]M_2=M-M*\frac_{1}{6.334}[/tex]

[tex]M_2=M*\frac{5.334}{6.334}[/tex]

Generally the equation for Gravitational force of attraction is mathematically given by

For Unequal split

[tex]F=\frac{GM_1M_2}{d^2}[/tex]

[tex]F=\frac{G(M*\frac_{1}{6.334})(M*\frac{5.334}{6.334})}{d^2}[/tex]

[tex]F=\frac{GM^2}{d^2}*(0.132)[/tex]

For equal split

[tex]F=\frac{GM_1M_2}{d^2}[/tex]

[tex]F=\frac{G(\frac{M}{2})((\frac{M}{2}}{d^2}[/tex]

[tex]F=0.25 \frac{GM^2}{d^2}[/tex]

Therefore the ratio of the gravitational force is

[tex]F_r=0.132:0.25[/tex]

Answer:

a) Dielectric constant ( λ ) = 750 * 10^-9 m

   minimum thickness of coating ( d )  = 187.5 nm

b) 3.6%

Explanation:

Given data:

wavelength of red light in air = 750 nm

εr = 4

μr = 1,  σ = 0

a) Determine the required dielectric constant and min thickness of coating used

Refractive index of coating ( n ) = √εr * μr =  √4*1 = 2

the refractive index of glass( ng)  = 1.5 which is < 2

λ = 750 * 10^-9 m

Dielectric constant ( λ ) = 750 * 10^-9 m

To determine the minimum thickness we will apply the formula below

d = m λ/2n ;  where  m = 1

∴ d = 750 nm / 2 ( 2 )

      = 187.5 nm

minimum thickness of coating ( d )  = 187.5 nm

b) Determine the percentage of the incident power that will be reflected

R = [ ( n-1 / n + 1 ) - ( n - ng / ng + n ) ]^2

   = [ ( 2 - 1 / 2 + 1 ) - ( 2 - 1.5 / 1.5 + 2 ) ]^2

   = 0.03628 =  3.6%

Answer:

[tex]u=13.3cm[/tex]

Explanation:

From the question we are told that:

Focal Length [tex]F=10.0cm[/tex]

Distance [tex]d=40cm[/tex]

Generally the equation for Focal length  is mathematically given by

[tex]\frac{1}{f}=\frac{1}{u}+\frac{1}{v}[/tex]

[tex]\frac{1}{10}=\frac{1}{u}+\frac{1}{40}[/tex]

[tex]\frac{1}{u}=\frac{3}{40}[/tex]

[tex]u=13.3cm[/tex]

Focal length is the distance from the center of the lens to principle foci.  The distance of the from the lens to the light bulb is 13.3 cm.

The distance can be determined by the formula,

[tex]\bold {\dfrac 1{f} = \dfrac 1{u} + \dfrac 1{v} }[/tex]

Where,

f - focal length = 10 cm

u - distance of object = ?

v = distance of image = 40 cm

Put the values in the equation,

[tex]\bold {\dfrac 1{10} = \dfrac 1{u} + \dfrac 1{40} }\\\\\bold {\dfrac 1{u} = \dfrac 3{40}}\\\\\bold {\dfrac 1{u} = 13.3 cm}[/tex]

Therefore, the distance of the from the lens to the light bulb is 13.3 cm.

To know more about the focal length,

https://brainly.com/question/13091382

Answer:

v = 5.15 m/s

Explanation:

At constant velocity, the cable tension will equal the car weight of 984(9.81) = 9,653 N

As the cable tension is less than this value, the car must be accelerating downward.

7730 = 984(9.81 - a)

a = 1.95 m/s²

kinematic equations s = ut + ½at² and v = u + at

-5.00 = u(4.00) + ½(-1.95)4.00²

u = 2.65 m/s    the car's initial velocity was upward at 2.65 m/s

v = 2.65 + (-1.95)(4.00)

v = -5.15 m/s

Answer:

packets of pen

packets of pencil

copies

books

bottles

mask

Six items that a student can sell in school at a profit:

- Homemade baked goods

- School supplies

-Drinks

- Healthy snacks

- Personalized accessories

- Stickers

Profit is the difference between the revenue earned by a business or individual and the costs incurred to produce the goods or services sold.

It is an important measure of financial success for companies and is often used to determine the value of a business.

We have,

Here are six items that a student can sell in school at a profit:

Homemade baked goods - cupcakes, cookies, brownies, and other treats can be sold individually or as a pack.

School supplies - items such as pens, pencils, erasers, rulers, notebooks, and binders are always in demand.

Drinks - bottled water, juices, and sodas are popular beverages that students may purchase during the school day.

Healthy snacks - fresh fruit, granola bars, and trail mix are nutritious snacks that many students are interested in buying.

Personalized accessories - items like keychains, bracelets, and bookmarks with unique designs or student names can be popular among peers.

Stickers - fun and colorful stickers can be sold individually or in packs and are often a favorite of younger students.

Thus,

Six items that a student can sell in school at a profit:

- Homemade baked goods

- School supplies

-Drinks

- Healthy snacks

- Personalized accessories

- Stickers

Learn more about profit here:

https://brainly.com/question/15699405

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Answer:

-4/7

Explanation:

Given the following

A=4i-10j and B= 7i+5j

A+ bB = 4i-10j + (7i+5j)b

A+ bB =  4i-10j + 7ib+5jb

A+ bB =

The vector along the x-axis is expressed as i + 0j

If the vector A+ bB is pointing in the direction of the x-axis then;

[tex]A+ bB * \frac{i+0j}{|i+0j|} = 0 \\ (4+7b)i-(10-5b)j* \frac{i+0j}{\sqrt{1^2+0^2} } = 0\\(4+7b)i-(10-5b)j *(i+0j) = 0\\4+7b-0 =0\\7b=-4\\b = -4/7[/tex]

Hence the value of b is -4/7

The value of [tex]\beta[/tex] such that [tex]\vec C = \vec A + \beta \cdot \vec B = c\,\hat{i}[/tex] is 2.

According to the statement, we have following system of vectorial equations:

[tex]\vec A = 4\,\hat {i} - 10\,\hat{j}[/tex] (1)

[tex]\vec {B} = 7\,\hat{i} + 5\,\hat{j}[/tex] (2)

[tex]\vec C = \vec A + \beta \cdot \vec B = c\,\hat{i}[/tex] (3)

By applying (1) and (2) in (3):

[tex](4\,\hat{i}-10\,\hat{j}) + \beta\cdot (7\,\hat{i}+5\,\hat{j}) = c\,\hat{i}[/tex]

[tex](4+7\cdot \beta)\,\hat{i} +(-10+5\cdot \beta)\,\hat{j} = c\,\hat{i}[/tex]

And we get two scalar equations after analyzing each component:

[tex]4+7\cdot \beta = c[/tex] (4)

[tex]-10+5\cdot \beta = 0[/tex] (5)

We solve for [tex]\beta[/tex] in (5):

[tex]\beta = 2[/tex]

And for [tex]c[/tex] in (4):

[tex]c = 4+7\cdot (2)[/tex]

[tex]c = 18[/tex]

The value of [tex]\beta[/tex] such that [tex]\vec C = \vec A + \beta \cdot \vec B = c\,\hat{i}[/tex] is 2.

Please see this question related to Sum of Vectors for further details: https://brainly.com/question/11881720

Answer:

[tex]I_2=6.8A[/tex]

Explanation:

From the question we are told that:

Turns of inner coil [tex]N_1=120[/tex]

Radius of inner coil [tex]r_1=0.012m[/tex]

Current of  inner coil [tex]I_1=6.0A[/tex]

Turns of Outer coil [tex]N_2=150[/tex]

Radius of Outer coil [tex]r_2=0.017m[/tex]

Generally the equation for Magnetic Field is mathematically given by

[tex]B =\frac{ \mu N I}{2R}[/tex]

Therefore

Condition for the net Magnetic field to be zero

[tex]\frac{N_1* I_1}{( 2 * r_1 )}=\frac{N_2 * I_2}{2 * r_2}[/tex]

[tex]I_2=\frac{(N_1* I_1)*(( 2 * r_2)}{( 2 * r_1)*N_2}[/tex]

[tex]I_2=\frac{(120*6.0)*(( 2 * 0.017)}{( 2 * 0.012)*150}[/tex]

[tex]I_2=6.8A[/tex]

I'm not very good at this material. I'll try it, but if I were you, I wouldn't bet money on these answers.

"Isobaric" means constant pressure. So those are the horizontal lines, where every point on the line is at the same pressure. Those are the processes 1>2 and 3>4 .

I'm going around and around in my mind with the other labels, and I can't decide. So I'm afraid I can't answer any more of them ... they might be wrong.

Answer:

1 -> 2 & 3 -> 4: Isobaric process

4 -> 1: Work done BY the system

2 -> 3: Work done ON the system

W(total): W = 0J

Explanation:

The two horizontal lines (1 -> 2 & 3 -> 4) are "Isobaric" since isobaric processes take place at constant pressure. I believe 4 -> 1 is "Work done BY the system" since pressure increases when there is an increase of thermal energy, in other words, the system is absorbing heat. This is why the volume increases from 1 -> 2 after the system has absorbed heat in 4 -> 1. Following the directions of the arrows, 2 -> 3 would be "Work done ON the system" since pressure is DECREASING, meaning temperature is also exiting the system. That's why the next step (3 -> 4) shows a decrease in volume. This model depicts a process that has a W(total) of 0 J because this is a cycle.

I hope this helps :))

Answer:

λ₂ = 357.3 nm

Explanation:

The expression for double-slit interference is

          d sin θ = m λ                 constructive interference

          d sin θ = (m + ½) λ        destructive interference.

The initial data corresponds to a constructive interference, they indicate that we are in the fourth order (m = 4), let's look for the separation of the slits

         d sin θ = m λ₁

now ask for destructive interference for m = 4

        d sin θ = (m + ½) λ₂

we match these two expressions

         m λ₁ = (m + ½) λ₂

         λ₂ = ( m / m + ½) λλ₁  

let's calculate

         λ₂ =[tex]\frac{4}{(4.000 +0.5) \ 401}[/tex]

        λ₂ = 357.3 nm

Answer:

I think D) less than 50 years

Biologically speaking, at the end of the mission, the astronaut's age would be less than 50 years. The correct option is d.

An astronaut observes and performs the experiments based on the universe.

A 30-year-old astronaut goes off on a long-term mission in a spacecraft that travels at speeds close to that of light. The mission lasts exactly 20 years as measured on Earth.

Due to special relativity, between space and Earth, both moving with different speeds.

The total age will be less than 30 +20 =50 years. In space, he is moving with speed of light. So, time will move slowly. As measured with respect to Earth, exact time spent in space 20 years will be less on Earth.

So, biologically speaking, at the end of the mission, the astronaut's age would be less than 50 years.

Thus, the correct option is d.

Learn more about astronaut.

https://brainly.com/question/11244838

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Answer:

4.73 × 10^5

Explanation:

Answer:poop

Explanation:

poop

Answer:

Because it is the result of two more fundamental units, a derived unit is termed that. For volume, the cubic meter (m³) is the fundamental unit of area. Any number that cannot be measured directly with any equipment is referred to as a derived unit. For example, we can't quantify a substance's density using a rule, scale, or bucket.

OAmalOHopeO

Answer:

in parallel combination : potential difference between two terminal of resistors are always constant. ... hence, potential difference ( voltage ) must be same across each resistor .

Explanation:

Following the definition of the center of mass, "In physics, the center of mass of a distribution of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero."

(see explanation below)

Answer:

Resistance of the armature coil = 6.61 ohms

Back emf developed at normal speed = 98.62 V (Approx.)

Current drawn by the motor at one-third normal speed = 12.73 A

Explanation:

Given:

Potential difference V = 117 V

Current = 17.7 A

Motor drawn current = 2.78 A

Find:

Resistance of the armature coil

Back emf developed at normal speed

Current drawn by the motor at one-third normal speed

Computation:

A] Resistance of the armature coil R = V/ I

Resistance of the armature coil = 117 / 17.7

Resistance of the armature coil = 6.61 ohms

B] Back emf developed at normal speed  = V- IR

Back emf developed at normal speed = 117 V - (2.78 A)(6.61 ohms)

Back emf developed at normal speed = 117 V - 18.37

Back emf developed at normal speed = 98.62 V (Approx.)

C] Current drawn by the motor at one-third normal speed = 17.7 A - (98.62/3)/(6.61 ohms)

Current drawn by the motor at one-third normal speed = 17.7 - 4.97

Current drawn by the motor at one-third normal speed = 12.73 A

Answer:

Explanation:

Kinematic equation

v = u + at

If UP is assumed to be the positive direction and we let gravity be 10 m/s² which will be in the downward direction so will be negative.

a) v = 6  + (-10)(0.5) = 1 m/s    the result is positive, so upward

b) v = 6  + (-10)(2) = -14 m/s    the result is negative, so downward

Answer:

375 is the answer.

Explanation:

Speed : Distance / Time taken

S: m/ s

s: 1500/4

375 m / s answer

Answer:

375m per minute

Explanation:

if you are looking for a diffrent unit just multiply your answer by however many minutes are in that time frame

Answer:

These four are rotary, oscillating, linear and reciprocating. Each one moves in a slightly different way and each type of achieved using different mechanical means that help us understand linear motion and motion control.

(I got this off the web so credits to the rightful owner and I hope you have good day :)

Answer:

 #_pile = 12 celdas

Explanation:

Lead acid sulfur batteries generate each cell a potential of 2 volts. By colonato to reach the voltage of 24 volts

        #_pile = 24/2

       #_pile = 12 cledas

serially connected

Answer:

A wavefront is the locus of all the particles which are in phase. A wavelet is an oscilation that starts from zero, then the amplitude increases and later decreases to zero

Solution :

1. We know that : Buoyant force = weight of the liquid displace

                                                  = volume displaced x density of the fluid

Now volume of the man = [tex]$\frac{\text{mass}}{\text{density}}$[/tex]

Mass = weight / g

         [tex]$=\frac{940}{9.8}$[/tex]

         = 95.92 kg

And density = 1000 [tex]kg/m^3[/tex]

Therefore,

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

           [tex]$=\frac{95.92}{1000}$[/tex]

           = 0.0959 [tex]m^3[/tex]

We know density of air = 1.225 [tex]kg/m^3[/tex]

∴ Mass of air displaced = 0.0959 x 1.225

                                       = 0.1175 kg

Weight of the air displaced = 1.1515 N

Therefore, the buoyant force = 1.1515 N

2). As the balloon is not accelerated, the net force acting on it is zero.

Thus the weight that acts downwards = buoyant force upwards

So, the weight of the air displaced = weight of the balloon

                                                          = 17000 N

Therefore, the mass of the air displaced = volume of the air displaced (volume of the balloon) x density of air

[tex]$\frac{17000}{9.8} = \text{volume of air} \times 1.225$[/tex]

[tex]$\text{Volume of air displaced} = \frac{1700}{9.8 \times 1.225}$[/tex]

                                     = 1416.0766 [tex]m^3[/tex]