Suppose the maximum safe intensity of microwaves for human exposure is taken to be 1.00 W/m2. (a) If a radar unit leaks 50.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away (in cm) must you be to be exposed to an intensity considered to be safe

Answer:

421.83 m.

Explanation:

The following data were obtained from the question:

Height (h) = 396.9 m

Initial velocity (u) = 46.87 m/s

Horizontal distance (s) =...?

First, we shall determine the time taken for the ball to get to the ground.

This can be calculated by doing the following:

t = √(2h/g)

Acceleration due to gravity (g) = 9.8 m/s²

Height (h) = 396.9 m

Time (t) =.?

t = √(2h/g)

t = √(2 x 396.9 / 9.8)

t = √81

t = 9 secs.

Therefore, it took 9 secs fir the ball to get to the ground.

Finally, we shall determine the horizontal distance travelled by the ball as illustrated below:

Time (t) = 9 secs.

Initial velocity (u) = 46.87 m/s

Horizontal distance (s) =...?

s = ut

s = 46.87 x 9

s = 421.83 m

Therefore, the horizontal distance travelled by the ball is 421.83 m

Answer:

The best description of the general direction that the blue line points is East direction

Answer:

c. east

Explanation:

Answer:

First, let's think in the vertical problem:

The acceleration will be the gravitational acceleration:

g = 9.8 m/s^2

a = -9.8 m/s^2

For the velocity, we integrate over time:

v(t) = (-9.8 m/s^2)*t + v0

Where v0 is the initial velocity, in this case  v0 = 30m/s.

v(t) =  (-9.8 m/s^2)*t + 30m/s

Now, for the position we integrate again over time, and get:

P(t) = (1/2)*(-9.8 m/s^2)*t^2 + 30m/s*t + p0

Where p0 is the initial position, as the ball is launched from the ground, we can use p0 = 0m

p(t) = (-4.9m/s^2)*t^2 + 30m/s*t

Now, the maximum vertical height is reached when:

v(t) = 0m/s = -9.8m/s^2*t + 30m/s

t = 30m/s/9.8m/s^2 = 3.06s

Now we can evaluate the vertical position in t = 3.06s

p(3.06s) = (-4.9m/s^2)*(3.06)^2 + 30m/s*3.06 = 62m

So, rounding down, the correct option is: C. 60 m

Answer:

A. Continent material

Explanation:

Eruptions of molten material, which results in continent material is a piece of evidence of seafloor spreading.

Continent material is one piece of evidence of seafloor spreading. Option b is correct.

Seafloor spread is a phenomenon that happens along mid-ocean ridges, when new oceanic crust is generated by volcanic activity and then progressively travels away from the ridge.

The geological activity of seafloor spreading occurs when tectonic plates split apart.

Continent material is one piece of evidence of seafloor spreading.

Hence, option b is correct.

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Answer:

According to the question ,

Source point is A and the destination point is D

We have to find the distance of AD

From figure,

AE = AB - EB

EB = DC and ED = BC

Therefore in triangle AED

AD² = AE² + ED²

AD² = 4² + 3²

AD² = 16 + 9

AD² = 25

AD = 5

So , the man is 5km far from the starting point

Hope this helps and pls mark as brainliest :)

Answer:

55 MW.

Explanation:

So, we are given the following data or parameters Below;

=> "2.0 MW is to arrive at a large shopping mall over two 0.100Ω line.

=> " the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120 V."

=> "Assume the transformers are each 99% efficient."

STEP ONE: determine the current in the transmission line.

Output Current, i = Power/ voltage.

Output Current,i = (2.0 MW × 10^6 W/ 1 MW)/120.

Output Current,i = 1.66 × 10^4 A.

Therefore, current in the transmission line = output voltage × output current/99% × line voltage.

= 120 × 1.66 × 10^4/ 99% × 1200 = 1.68 × 10^3 A.

STEP TWO: determine the power loss in the two lines.

Power loss = i^2 × Resistance

Power loss = (1.66 × 10^4 )^2 × 0.1 × 2 = 5.5 × 10^7 watt.

STEP THREE: determine the power generated.

Power generated = 2 × 10^6 +5.5 × 10^7.

Power generated = 5.57 × 10^7 watt.

STEP FOUR: determine the step down transformer power.

= 2 × 10^6/99% = 2.02 × 10^6.

Thus, 2.02 × 10^6 + 5.57 × 10^5 = 2.58 × 10^6 watt.

STEP FIVE: Determine the total power and the saved power.

Total power = 2.58 × 10^6/ 99%= 2.6 × 10^6.

Saved power = 5.7 × 10^7 - 2.6 × 10^6 .

Conversion to MW gives saved power = 55 MW.

=

Answer:

  C.  lever

Explanation:

Any sort of prying tool is an example of a lever.

Answer:

A lever

Explanation:

Answer:

1.01×10^20 molecules of ozone.

Explanation:

Data obtained from the question include:

Volume (V) = 2 L

Temperature (T) = 275 K

Pressure (P) = 1.89×10¯³ atm

Gas constant (R) = 0.0821 atm.L/Kmol

Number of mole (n) of ozone =.?

Using the ideal gas equation, we can obtain the number of mole of ozone as follow:

PV = nRT

1.89×10¯³ x 2 = n x 0.0821 x 275

Divide both side by 0.0821 x 275

n = (1.89×10¯³ x 2) /(0.0821 x 275)

n = 1.67×10¯⁴ mole.

Therefore the number of mole of ozone in 2 L of air is 1.67×10¯⁴ mole.

Finally, we shall determine the number of molecules present in 1.67×10¯⁴ mole of ozone.

This can be obtained as follow:

From Avogadro's hypothesis, 1 mole of any substance contains 6.02×10²³ molecules. This implies that 1 mole of ozone contains 6.02×10²³ molecules.

If 1 mole of ozone contains 6.02×10²³ molecules,

therefore, 1.67×10¯⁴ mole of ozone will contain = 1.67×10¯⁴ x 6.02×10²³ = 1.01×10^20 molecules.

Therefore, 1.01×10^20 molecules of ozone are present in 2 L of air.

Answer:

[tex]\boxed{2}[/tex]

Explanation:

The GCF is the greatest common factor of the polynomial.

[tex]2x = 1, \ 2, \ x[/tex]

[tex]4y=1, \ 2, \ 4,\ y[/tex]

The greatest common factor is 2.

Answer:

50m/s

Explanation:

Formula:

velocity= distance/ time

velocity= 150/ 3

velocity= 50 m/s

I hope this helped you :)

When a  ball is launched horizontally at 150 m/s from a cliff then its horizontal velocity after 3 seconds would be 150 m/s, therefore the correct option is C.

The total displacement covered by any object per unit of time is known as velocity. It depends on the magnitude as well as the direction of the moving object. The unit of velocity is meter/second. It can also be represented by the infinitesimal rate of change of displacement with respect to time. The generally considered unit for velocity is a meter per second.

The mathematical expression for velocity is given by

velocity= total displacement/Total time

Suppose an object has a total displacement of 100 meters in a total time of 25 seconds its velocity would be 4 meter/seconds

For the given problem situation when a ball is launched horizontally at 150 m/s from a cliff then its horizontal velocity after 3 seconds would be 150 m/s  because the horizontal component of the velocity remains constant during a projectile motion, therefore, the correct option is C.

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Power consumption = (voltage) x (current)

Power = (120 V) x (1.5 A)

Power = 180 watts

But 1 watt = 1 Joule/second

180 watts = 180 Joule/second

Energy consumption of the light bulb =  

(180) x (number of seconds it's turned on)  Joules

Answer:

The values of a, b, c and d are

a = 3, b = 3, c = 4 and d = 3

Explanation:

The quantity of heat needed to melt the ice is given by Q = mL where m = mass of ice and L = latent heat of fusion of ice = 334 kJ/kg. This quanity of heat is also the thermal energy needed to be released by the calcium chloride, CaCl₂

Now, the mass of ice = 10 kg. So,

Q = mL

Q = 10 kg × 334 kJ/kg

Q = 3340 kJ

In scientific notation,

Q = 3.34 × 10³ kJ

So the thermal energy needed to be released by the calcium chloride is 3.34 × 10³ kJ

Comparing Q = 3.34 × 10³ kJ with a.bc × [tex]10^{d}[/tex] kJ

So, a = 3, b = 3, c = 4 and d = 3

The values of a, b, c and d are

a = 3, b = 3, c = 4 and d = 3

Answer:

The actual height of the tree is 28 m

Explanation:

The given information are;

The length of the shadow of an upright meter rule = 25 cm

The actual height of the meter rule = 100 cm

The length of the shadow of the tree = 7 m

The actual  height of the tree  = h

We have

[tex]\dfrac{The \ length \ of \ the \ shadow \ of \ an \ upright \ metre \ rule}{The \ actual \ height \ of \ the \ metre \ rule} = \dfrac{The \ length \ of \ the \ shadow \ of \ the \ tree}{The \ actual \ height \ of \ the \ tree}[/tex]Which gives;

[tex]\dfrac{25 \ cm}{100 \ cm} = \dfrac{7 \ m}{The \ actual \ height \ of \ the \ tree}[/tex]

Therefore;

[tex]The \ actual \ height \ of \ the \ tree = 7 \ m \times \dfrac{100 \ cm}{25\ cm} = 7 \ m \times 4 = 28 \ m[/tex]

That is the actual height of the tree = 28 m.

If we launched a very fast dart from the Space Shuttle in a direction away from any planet, Assuming the dart is traveling at an extremely high speed (close to the speed of light), it might eventually encounter a cloud of interstellar gas or dust.

Space is mostly empty, consisting of a vacuum with very low density. However, space also contains various astronomical objects, such as stars, planets, moons, asteroids, comets, and other celestial bodies.

There is also interstellar gas and dust scattered throughout space, which can sometimes form clouds that give birth to new stars. Additionally, space is permeated by electromagnetic radiation, including cosmic rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.

Space also contains various forms of energy, including dark energy, which is believed to be responsible for the accelerating expansion of the universe, and dark matter, which is thought to make up the majority of the matter in the universe but cannot be directly observed. Overall, space is a vast and complex environment that continues to fascinate astronomers and scientists.

Here in this question,

Therefore, if launched a very fast dart from the Space Shuttle, is pointed in some direction away from any planet, it could travel beyond the solar system. it would be most likely to hit a cloud of interstellar gas or dust. first after traveling outward for a while.

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Answer:

p=m÷v

Explanation:

that is the formula for it. now, using your numbers p=density,m=mass and v= volume. you just divide it.

after you measurement would be in cm/3

Answer:

You can simply find density by using formula

[tex]d = \frac{m}{v} [/tex]

where m represents mass of an object and v represents volume of an object.

hope it helps..

Answer:

C and D

Explanation:

A: is a simple composition

B: is a single replacement

C: C is a double displacement

D: is a double replacement

Answer:

The answers are C abd D.

Explanation:

Here,

A no. Is a combination or analysis chemical reaction.

B no.is a single displacement reaction as cl2 goes to zn.

C no. Is double displacement reaction.

D no. Is a double displacement reaction.

Hope it helps.....

Answer:

A. I and V

Explanation:

According to Le Chatelier's Principle, increasing the product side will cause the equilibrium to shift back towards the reactant side, so I is true.  By the same principle, II is false.

For gases, decreasing the pressure will cause the equilibrium to shift towards the side with higher number of moles.  So V is true.

The reaction is endothermic, so increasing the temperature will shift the equilibrium to the products, so IV is false.  And adding a catalyst has no effect on the equilibrium, so III is false.

The changes would result in more reactants being produced will increase NO₂ and decrease the pressure. Then the correct option is A.

The chemical reaction is the reaction between two reactants that led to the formation of products.

The products are substances that form after the reaction. The reactants are the substances that are original materials.

Given the reaction: N₂(g) +2O₂(g) ⇌ 2NO₂(g)

The forward reaction is endothermic. Increasing the product side will cause the equilibrium to shift back towards the reactant side, so I is true.  

By the same principle, II is false.

For gases, the decrease in pressure will shift the equilibrium toward the high number of moles side.  

So V is true.

The reaction is endothermic, so increasing the temperature will shift the equilibrium to the products, so IV is false.  Adding a catalyst has no effect on the equilibrium, so III is false.

The changes would result in more reactants being produced will increase NO₂ and decrease the pressure.

Then the correct option is A.

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Answer:

they get closer together

Explanation:

Answer:

119.6 J/Kg°C

Explanation:

Data obtained from the question include:

Mass of substance (ms) = 170 g

Initial temperature of substance (Ts) = 120 °C

Volume of water = 200 mL

Initial temperature of water (Ts) = 10 °C

Temperature of the mixture (T2) = 12.6 °C

Density of water = 1 g/mL

Specific heat capacity of water (Cw) = 4200J/Kg°C

Specific heat capacity of substance (Cs) =..?

Next, we shall determine the mass of water. This can be obtained as follow:

Volume of water = 200 mL

Density of water = 1 g/mL

Mass of water =..?

Density = mass /volume

1 = mass /200

Cross multiply

Mass of water = 1 x 200

Mass of water = 200 g

Convert 200 g of water to Kg

Mass of water = 200/1000 0.2 Kg

Mass of water = 0.2 Kg

Now, we obtained the specific heat capacity of the substance using the following formula:

MwCw(T2 – Tw) + MsCs(T2 – Ts) = 0

Mass of water = 0.2 Kg

Initial temperature of water (Ts) = 10 °C

Specific heat capacity of water (Cw) = 4200J/Kg°C

Temperature of the mixture (T2) = 12.6 °C

Mass of substance (ms) = 170 g = 170/1000 = 0.17 Kg

Initial temperature of substance (Ts) = 120 °C

Specific heat capacity of substance (Cs) =..?

MwCw(T2 – Tw) + MsCs(T2 – Ts) = 0

0.2× 4200(12.6 – 10) + 0.17×Cs×(12.6 – 120) = 0

840(2.6) + 0.17Cs(– 107.4) = 0

2184 – 18.258Cs = 0

Rearrange

2184 = 18.258Cs

Divide both side by the coefficient of Cs i.e 18258

Cs = 2184/18.258

Cs = 119.6 J/Kg°C

Therefore, the specific heat capacity of the substance is 119.6 J/Kg°C

Answer:

maximum shear stress = τ(max) = 95.49 × 10⁶N/m²

Explanation:

given

outer diameter at one end(D₁) = 3.0cm

outer diameter at the other end(D₂) = 4.0cm

inner diameter(d₁) = 1.0cm

torque applied(T) = 500Nm

maximum shear stress will occur at lower outer diameter

the formula is τ/r = T/J

τ= T × r/J

where r is radius

T is the torque

J is the polar 2nd M of area

attached is the calculation of the question

Answer:

my big long peen for ur mom

Explanation:

Answer:

Hello There. ☆~\《--_^■^_--》\~☆ The final velocity of the car A is -1.053 m/s. For an elastic collision both the kinetic energy and the momentum of the system are conserved.

Hope It Helps!~ ♡

ItsNobody~ ☆

Given:

[tex]M_A = 281 \ kg \\\\ v_A= 2.82 \frac{m}{s}\\\\M_B = 209 \ kg \\\\ V_B = 1.72 \frac{m}{s}[/tex]

To find:

velocity=?

Solution:

Using the formula for the velocity of CAR after the collision:

[tex]\to V_A = \frac{V_A(M_A -M_B) +2 M_B V_B}{M_A+M_B}\\\\[/tex]

         [tex]= \frac{2.82(281 - 209) +2 \times 209 \times 1. 72}{ 281+ 209}\\\\ = \frac{2.82(72) +718.96}{490}\\\\= \frac{203.04 +718.96}{490}\\\\= \frac{922.00}{490}\\\\= \frac{922}{490}\\\\=1.881 \ \frac{m}{s}[/tex]

Therefore, the answer is "[tex]\bold{1.881\ \frac{m}{s}}[/tex]"

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Answer:

the answer B

Explanation:

Answer:

Explanation:

We shall apply gas law formula to get the solution .

P₁ V₁ / T₁ = P₂ V₂ / T₂

P₁ = 10⁵ + 18 x 10³ x 9.8  where 10⁵ Pa is atmospheric  pressure at surface

= 1.764 x 10⁵ + 10⁵

= 2.764 x 10⁵

2.764 x 10⁵  x 3 / ( 273 + 9 ) = 10⁵ x V₂ / ( 273 + 22 )

V₂ = 8.67 cm³

The only thing that mkes this question inconvenient is that it uses a mixture of units ... speed in km/hr, and acceleration in m/s².  You can't directly mash those together.

What's the speed when we express it in m/s ?

Speed = (90 km/hr) · (1,000 m/km) · (1 hr/3,600 sec)

Speed = (90 · 1,000 · 1 / 3,600) · (km-m-hr / hr-km-sec)

Speed = 25 m/s

OK great !  

-- The car is traveling at 25 m/s when the brakes are applied.

-- The brakes slow it down by 0.5 m/s every second.

-- So it takes (25/0.5) = 50 seconds to stop the car.

-- During that time, the car's average speed is (1/2)·(25m/s + 0) = 12.5 m/s .

-- Moving at an average speed of 12.5 m/s for 50 sec, the car travels

(12.5 m/s) · (50 s)  =  625 meters

Answer:

D

Explanation:

The most suitable testable question. in this case, would be that 'are there more home runs during the more humid months of the  summer?'

Since the aim of the investigation is to find the relationship between humidity and the number of home runs, measuring the number of home runs during the more humid months in the summer and comparing the data to the number of home runs during the less humid months in the same summer would provide the answer.

Only option D raises a valid question that is relevant to the aim of the investigation.

Answer:

12.7 m

Explanation:

The following data were obtained from the question:

Initial velocity (u) = 56.7 Km/hr

Maximum height (h) =..?

First, we shall convert 56.7 Km/hr to m/s. This can be obtained as follow:

Initial velocity (m/s) = 56.7 x 1000/3600

Initial velocity (m/s) = 15.75 m/s

Next, we shall determine the time taken to get to the maximum height. This can be obtained as follow:

Initial velocity (u) = 15.75 m/s

Final velocity (v) = 0 m/s

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =?

v = u – gt (since the ball is going against gravity)

0 = 15.75 – 9.8 × t

Rearrange

9.8 × t = 15.75

Divide both side by 9.8

t = 15.75/9.8

t = 1.61 secs.

Finally, we shall determine the maximum height as follow

h = ½gt²

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) = 1.61 secs.

Height (h) =..?

h = ½gt²

h = ½ × 9.8 × 1.61²

h = 4.9 x 1.61²

h = 12.7 m

Therefore, the maximum height reached by the ball is 12.7 m

Answer:

The trouble that the most recent experiment, Borexino, have to overcome was that

neutrinos hardly interact with matter and so radioactive decay of ant material inside the detector could look exactly like a neutrino interaction too

Answer:

10 rad/s

Explanation:

The gears have the same linear speed.

ω₁ r₁ = ω₂ r₂

(25 rad/s) (2R) = ω (5R)

ω = 10 rad/s