A car travels 8km in 7 minutes. Find the speed of the car.

Answer:

E = 75 J

Explanation:

First, we will calculate the total power consumed by the five lamps:

[tex]Total\ Power = P = (5)(Power\ of\ one\ lamp)\\P = (5)(3\ W)\\P = 15\ W[/tex]

Now, the energy supply can be calculated as follows:

[tex]E = Pt[/tex]

where,

E = Energy = ?

t = time = 5 s

Therefore,

E = (15 W)(5 s)

E = 75 J

Answer:

the percentage of heat lost by the window is 93.18%

Explanation:

Given the data in the question;

Area of glass [tex]A_{glass[/tex] = 0.10 m²

Thickness of glass [tex]t_{glass[/tex] = 8 mm = 0.008 m

Area of Styrofoam [tex]A_{styrofoam[/tex] = 11 m²

Thickness of Styrofoam [tex]t_{styrofoam[/tex] = 0.15 m

we know that;

Thermal conductivity of glass [tex]k_{glass[/tex] =  0.80 J/smC°

Thermal conductivity of Styrofoam  [tex]k_{styrofoam[/tex] =  0.010 J/smC°

Now, temperature difference between outside and inside the walls and window is ΔT

So, In time t, heat lost due to conduction in the window will be;

[tex]Q_{glass[/tex] = [[tex]k_{glass[/tex] × [tex]A_{glass[/tex]  × ΔTt] / [tex]t_{glass[/tex]

we substitute

[tex]Q_{glass[/tex] = [ 0.80 × 0.10 × (ΔT)t] / 0.008

[tex]Q_{glass[/tex] = [ 0.80 × 0.10 × (ΔT)t] / 0.008  

[tex]Q_{glass[/tex] = 10(ΔT)t J

Also, the heat lost due to conduction in the wall be;

[tex]Q_{styrofoam[/tex] =  [[tex]k_{styrofoam[/tex] × [tex]A_{styrofoam[/tex] × ΔTt] / [tex]t_{styrofoam[/tex]

we substitute

[tex]Q_{styrofoam[/tex] =  [ 0.010 × 11 × ΔTt] / 0.15

[tex]Q_{styrofoam[/tex] =  0.7333(ΔT)t J

Now, Net heat lost in the wall and window is;

Q = [tex]Q_{glass[/tex] + [tex]Q_{styrofoam[/tex]

Q = 10(ΔT)t J + 0.7333(ΔT)t J

Q = 10.7333(ΔT)t J

So, the percentage of heat lost by the windows will be;

% of heat lost = [tex]Q_{glass[/tex] / Q

= 10(ΔT)t J / 10.7333(ΔT)t J

= 0.93167

= ( 0.93167 × 100 )%

= 93.18%

Therefore, the percentage of heat lost by the window is 93.18%

Explanation:

A push or pull of an objecr

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

A force is described as push or pull on an object.

Answer:

he has more pushing force than the truck there for pushing it forword.

Explanation:

If ' c ' is the speed of light, then the formula for it is . . .

c = 299,792,458 meters per second

Answer:

(D) energy from one place to another

Answer:

Materials like air, water, and clear glass are called transparent. When light encounters transparent materials, almost all of it passes directly through them. ... When light strikes translucent materials, only some of the light passes through them. The light does not pass directly through the materials.

Explanation:

Answer:

The final angular velocity is rev/s is 0.293 rev/s.

Explanation:

Given;

mass of the merry-go-round, m₁ = 120 kg

radius of the merry-go-round, r = 1.8 m

initial angular velocity, ω = 0.4 rev/s

mass of the child, m₂ = 22 kg

Apply the principle of conservation angular momentum to determine the final angular velocity;

[tex]I_i= I_f\\\\\frac{1}{2} m_1r^2 \omega _i = \frac{1}{2} m_1r^2 \omega _f + m_2r^2 \omega _f\\\\ \frac{1}{2} m_1r^2 \omega _i =( \frac{1}{2} m_1r^2 + m_2r^2 )\omega _f\\\\\omega _f = \frac{ \frac{1}{2} m_1r^2 \omega _i}{\frac{1}{2} m_1r^2 + m_2r^2} \\\\\omega _f = \frac{ \frac{1}{2} m_1 \omega _i}{\frac{1}{2} m_1 + m_2}\\\\\omega _f = \frac{0.5 \ \times \ 120\ kg \ \times \ 0.4\ rev/s}{0.5 \ \times 120\ kg \ \ + \ \ 22 \ kg} \\\\\omega _f = 0.293 \ rev/s\\[/tex]

Therefore, the final angular velocity is rev/s is 0.293 rev/s.

Explanation:

Work done= MGH

180=m×10×3

180/30=m

m=6kg

Answer:

a=vf - vi/t

vf=final velocity

vi= initial velocity

t=time period

Now The bicycle went from 3ms to 1ms...

1.. It decelerated

2... Since it went from 3 to 1... 1 is the final velocity while 3 is the initial Velocity

Applying the Formula

a= 1-3/2

= -2/2

a= -1ms-²

Option D

Answer:

Material that allow the electrons to move freely in order to produce a current

Please mark as brainliest if answer is right

Have a great day, be safe and healthy  

Thank u  

XD  

Answer:

[tex]380697.33\ \text{N/m}[/tex]

[tex]0.138\ \text{m}[/tex]

Explanation:

m = Mass rocket = 1070 kg

v = Velocity of rocket = 3.75 m/s

a = Acceleration of rocket = 5g

g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]

The energy balance of the system is given by

[tex]\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2\\\Rightarrow kx=\dfrac{mv^2}{x}\\\Rightarrow kx=\dfrac{1070\times 3.75^2}{x}\\\Rightarrow kx=\dfrac{7250}{x}[/tex]

The force balance of the system is given by

[tex]ma=kx\\\Rightarrow m5g=\dfrac{7250}{x}\\\Rightarrow x=\dfrac{7250}{1070\times 5\times 9.81}\\\Rightarrow x=0.138\ \text{m}[/tex]

The distance the spring must be compressed is [tex]0.138\ \text{m}[/tex]

[tex]k=\dfrac{7250}{x^2}\\\Rightarrow k=\dfrac{7250}{0.138^2}\\\Rightarrow k=380697.33\ \text{N/m}[/tex]

The force constant of the spring is [tex]380697.33\ \text{N/m}[/tex].

Answer:

I think it's A

Explanation:

It's definitely not B on edge

The correct option for the given question about Einstein's general

theory of relativity is Option A) Mars, Venus, Uranus, Neptune.

As a Conclusion, we can state that the planets who would cause curvature in space time from the least amount of curvature to the greatest will be in order Mars, Venus, Uranus, Neptune.

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Answer:

iek

Explanation:

Answer:

the answer to your questions above is 3 x 4 = 12 volts

Explanation:

Voltage =  Current × Resistance

Answer: 0 m/s. that is your answer i hope this help sorry if i am wrong

Explanation:

What does the area under the curve on a velocity-versus-time graph represent? ... then slows down to travel the last 40 miles in three hours. ... 20. A bicyclist travels the first 700 m of a trip at an average speed of 8 m/s, travels the ... to complete the trip at an average speed, for the entire trip of 440 km/h. ... 125) v1= 0 m/s.

Answer:

0.187 m

Explanation:

We'll begin by calculating the acceleration of the ball. This can be obtained as follow:

Mass (m) = 0.450 Kg

Force (F) = 38 N

Acceleration (a) =?

F = m × a

38 = 0.450 × a

Divide both side by 0.450

a = 38 / 0.450

a = 84.44 m/s²

Finally, we shall determine the distance. This can be obtained as follow:

Initial velocity (u) = 2.20 m/s.

Final velocity (v) = 6 m/s

Acceleration (a) = 84.44 m/s²

Distance (s) =?

v² = u² + 2as

6² = 2.2² + (2 × 84.44 × s)

36 = 4.4 + 168.88s

Collect like terms

36 – 4.84 = 168.88s

31.52 = 168.88s

Divide both side by 168.88

s = 31.52 / 168.88

s = 0.187 m

Thus, the distance is 0.187 m

Answer:

Explanation:

The center of gravity  will act at the middle point that is at 4.38 m from the end of the plank that is on boat . 16.35 x 9.8 N will act at this point .

The plank will turn around a point at 3.17 m from the end of plank that is on boat .

Suppose the weight required be W . It will be placed at the end of the plank that is on boat . The position of man is on the extreme end of the plank that is over water . So its distance from turning point will be 8.76 - 3.17 = 5.59 m .

Taking torque about turning point of all the forces like , weight of plank , weight of the person walking and force due to W

W   x 3.17 =  16.35 x ( 4.38 - 3.17 ) + 60.3 x ( 8.76 - 3.17 )

W   x 3.17 =  19.78  + 337.07 = 356.85

W = 112.57 kg .

We/Wm = ge/gm = 120N/1.2N

or

gm = ge/100 = 0.1 m/s^2

density = mass/volume = 3M/(4pir^3)

Re-arranging this equation, we get

M/r^2 = (4/3)×pi×(density)×r

From Newton's universal law of gravitation, the acceleration due to gravity on the moon gm is

gm = G(M/r^2) = G×(4/3)×pi×(density)×r

Solving for density, we get the expression

density = 3gm/(4×pi×G×r)

= 3(0.1)/(4×3.14×6.67×10^-11×2.74×10^6)

= 130.6 kg/m^3

Answer: a different one is a.b.c

Explanation: still for ape.x

The correct order to determine the age of the an object using carbon-14 is C, A, B. Thus, option D is correct.

The half-life time is defined as the time taken by the radioactive element to reduce one half of its initial value. It is denoted by t(1/2).

To measure the age of an object, a radioactive isotope called carbon-14 is used. The half-life of carbon-14 is 5,730 years. All the objects in the universe consumes carbon  in their lifetime and hence, carbon-14 is used to measure the age of the objects.

The process of determining the age of objects using carbon-14 is called Radiocarbon dating. All living organisms consume carbon in means of food and from atmosphere and when the plant and animals dies, the radioactive carbon atoms start decaying.

When it starts decaying, by using Carbon-14 the age of an object is calculated. The age is estimated by measuring the amount of carbon-14 present in the sample and comparing this carbon with the reference Carbon-14 isotope.

The amount of carbon in  preserved plants is identified by:

f(t) = 10e {₋ct}  

t = time in years when the plant dies( t= 0)

c = the amount of carbon-14 remaining in preserved plants.

The steps include to find the age of an object is :

1. Use the number of half-lives that have passed to determine the age of the object.

2. Use the half-life of carbon-14 to determine the number of half-lives that have passed.

3.Measure the ratio of parent nuclei to daughter nuclei.

Hence, from these steps the age of an object is determined. Therefore the correct solution is D) C, A, B.

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Answer:

it's C

Explanation:

The colder side of the Moon always faces away from the Sun.

Answer:

Percentage:

Rr = 50% because it's 2/4 (for both or 25% each since you have them separate)

rr = also 50%, because it's also 2/4.

Phenotype:

Rr = heterozygous

rr = "hozygous" recessive

In addition, RR is "hozygous" dominant

Explanation:

They said the hozygous is a swearword LOL.

Answer: Electrons move from the potassium atoms to the sulfur atoms.

Explanation:  2 K + S ⇒ 2 K^+ + S^2-   . Usually metals donor electrons to non-metals

Answer:

The work done by you on the two cart system is 2 N-m

Explanation:

Work done is the product of force and displacement.

W = F * D

Substituting the given values we get -

W =

[tex]4 * (0.17+0.33)\\= 2[/tex]

The work done by you on the two cart system is 2 N-m

In order to make it all the way from the opening to the detector, a wave has to travel through air, glass, water, plastic, and vacuum.

-- The siren and the tuning fork are sounds.

-- Sound cannot travel through vacuum.

-- That knocks out choices B, C, and D.

The answer is A.

Note:  Making a big exception here.  We don't do test questions on Brainly. That would be cheating. Don't let me catch you doing it again.

Answer:

6.8 N.m

Explanation:

The computation of the magnitude of the magnetic torque on the coil is given below:

Given that

n = 400

d =  6.0 cm

Current  is I = 7.0 A

Angle is [tex]\theta[/tex] = 30 degree

Now

We know that

the magnitude of the magnetic torque is

= nIABsin[tex]\theta[/tex]

= (400) (7.0) π ÷ 4 (0.06m)^2 sin(90° - 30°)

As

[tex]\theta[/tex] = (90° - Ф)

=  (400) (7.0) π ÷ 4 (0.06m)^2 sin 60°

= 6.8 N.m

Answer:

The new angular speed of the merry-go-round = [tex]1.6rad/sec[/tex]

Explanation:

From angular momentum conservation

[tex]Iw_1 = (I + mr^2)w_2\\\\3*100 = (100 + 22*2^2)w_2\\\\300 = (100 + 88)w_2\\\\w_2 = \frac{300}{188}\\\\w_2 = 1.6rad/sec[/tex]

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