The archerfish uses a remarkable method for catching insects sitting on branches or leaves above the waterline. The fish rises to the surface and then shoots out a stream of water precisely aimed to knock the insect off its perch into the water, where the archerfish gobbles it up. Scientists have measured the speed of the water stream exiting the fish's mouth to be 3.7 m/s. An archerfish spots an insect sitting 18 cm above the waterline and a horizontal distance of 28 cm away. The fish aims its stream at an angle of 39° from the waterline.

Required:
Determine the height above the waterline that the stream reaches at the horizontal position of the insect.

Answer:

[tex]f=1.57\times 10^9\ Hz[/tex]

Explanation:

Given that,

A system can detect objects as small as 19.1 cm i.e. 0.191 m. It is the wavelength.

We know that,

Frequency, [tex]f=\dfrac{c}{\lambda}[/tex]

So,

[tex]f=\dfrac{3\times 10^8}{0.191}\\\\=1.57\times 10^9\ Hz[/tex]

So, the frequency of such a system is equal to[tex]1.57\times 10^9\ Hz[/tex].

Answer: 4

Explanation:

MA = output force / input force

MA = 20 / 5

MA = 4

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Answer: The amount of energy transferred to each eardrum in one second is [tex]6.2 \times 10^{-9} J[/tex].

Explanation:

Given: Intensity = 0.10 [tex]W/m^{2}[/tex]

Now, at 30.0 m the intensity will be calculated as follows.

[tex]Intensity = \frac{(30.0 m)^{2}}{(1 m)^{2}}\\= 900[/tex]

This means that the intensity is 900 times less assuming that the wave is spherical.

Hence, the new intensity is calculated as follows.

[tex]\frac{0.10 W/m^{2}}{900}\\= 1.11 \times 10^{-4} W/m^{2}[/tex]

The area of ear drum is expressed as follows.

[tex]Area = \pi \times r^{2}\\= 3.14 \times (4.2 mm)^{2}\\= 5.54 \times 10^{-5} m^{2}\\[/tex]

Formula used to calculate energy is as follows.

[tex]P = I \times a[/tex]

where,

P = power or energy

I = intensity

a = area

Substitute the values into above formula as follows.

[tex]P = I \times a\\= 1.11 \times 10^{-4} W/m^{2} \times 5.54 \times 10^{-5} m^{2}\\= 6.2 \times 10^{-9} W[/tex]

Thus, we can conclude that amount of energy transferred to each eardrum in one second is [tex]6.2 \times 10^{-9} J[/tex].

Answer:

Because molecules are to small for us people to see with the bare eye, unless you use a telescope.

Explanation:

Explanation:

Because in solid form, the molecules stood in place, not moving. In liquid state, the molecules move slowly but not as fast as air molecules.

Answer:

A) v = 21 m /s

B) 25%

C) ) on collision, this energy in the question appears in the form of the following namely; sound energy, heat energy etc

Explanation:

A) Let m be the mass of any of the cars

Thus:

mass of the three cars = 3m

Formula for kinetic energy = ½mv²

Thus, Kinetic energy of 3 identical and coupled cars = ½ x 3m x 28² = 1176 m

KE = 1176 m

Now mass of 4 coupled cars together = 4m

From conservation of linear momentum, we can find the speed of the four cars. Thus;

m1v1 = m2v2

We are told that the 3 coupled moved together with a speed of 28 m/s

Thus;

4m × v = 3m × 28

v = 3m x 28 / 4m

v = 21 m /s

B) from earlier, we saw the formula for kinetic energy. Thus, kinetic energy with of mass of 4 coupled cars together. Thus;

K = ½ x 4m x 21²

K = 882m

Loss of kinetic energy

ΔK = 1176 m - 882 m

ΔK = 294 m

Therefore, percentage of loss is;

%loss = (294 / 1176 ) x 100

%loss = 25 %

C) on collision, this energy in the question appears in the form of the following namely; sound energy, heat energy etc

Answer:

Explanation:

Given that:

mass = 10kg

damping constant C = 15 kg/s

length = 2 m

Force F = 6N

Using the Hooke's law:

F = kx

6 = 15x

k = 6 N /2 m

spring constant k = 3 N/m

For the critical damping

C² - 4k*m= 0

m = C²/4k

m = (15)²/4(3) kg

m = 225/12 kg

m = 18.75 kg

Answer:

friction is motion heat that collect hot vibration

Answer:

electromagnetism....

Answer:

[tex]I_2=0.50 w/m^2[/tex]

Explanation:

From the question we are told that:

initial Intensity [tex]I_1=0.020 w/m^2[/tex]

Final Electric field [tex]E_2=5E[/tex]

Generally the equation for Relation ship between intensity and Electric field is mathematically given by

 [tex]\frac{I_1}{I_2}= \frac{E_1^2}{E_2^2}[/tex]

Therefore

 [tex]I_2=\frac{I_1}{ \frac{E_1^2}{E_2^2}}[/tex]

 [tex]I_2=\frac{0.020}{ \frac{E^2}{5E^2}}[/tex]

 [tex]I_2=0.50 w/m^2[/tex]

Answer:

460.52 s

Explanation:

Since the instantaneous rate of change of the voltage is proportional to the voltage in the condenser, we have that

dV/dt ∝ V

dV/dt = kV

separating the variables, we have

dV/V = kdt

integrating both sides, we have

∫dV/V = ∫kdt

㏑(V/V₀) = kt

V/V₀ = [tex]e^{kt}[/tex]

Since the instantaneous rate of change of the voltage is -0.01 of the voltage dV/dt = -0.01V

Since dV/dt = kV

-0.01V = kV

k = -0.01

So, V/V₀ = [tex]e^{-0.01t}[/tex]

V = V₀[tex]e^{-0.01t}[/tex]

Given that the voltage decreases by 90 %, we have that the remaining voltage (100 % - 90%)V₀ = 10%V₀ = 0.1V₀

So, V = 0.1V₀

Thus

V = V₀[tex]e^{-0.01t}[/tex]

0.1V₀ = V₀[tex]e^{-0.01t}[/tex]

0.1V₀/V₀ = [tex]e^{-0.01t}[/tex]

0.1 = [tex]e^{-0.01t}[/tex]

to find the time, t it takes the voltage to decrease by 90%, we taking natural logarithm of both sides, we have

㏑(0.01) = -0.01t

So, t = ㏑(0.01)/-0.01

t = -4.6052/-0.01

t = 460.52 s

According to Coulomb's law, rank the interactions between charged particles from highest potential energy to lowest potential energy.

Highest potential energy to lowest potential energy.

b. 1+ charge and 1+ charge seperated by 100 pm

a. 1+ charge and 1- charge seperated by 200 pm

c. 1+ charge and 1- charge seperated by 100 pm

d. 2+ charge and 1- charge seperated by 100 pm

[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]

Answer:

The glass rod remains charged due to electrification by the silk

Answer:

u=8.868 m/s

Explanation:

The displacement of the ball is 4 meters

The final speed of the ball is 0.5 m/s

The initial speed of the ball is to be calculated. Using the equation of the rectilinear motion,

[tex]v^{2} =u^{2} +2as[/tex]

Plugging the values in the above expression,

[tex]\\0.5^{2} =u^{2} +2*(-9.8)*4\\\\u^{2} =78.4+0.25\\\\u^{2} =78.65\\\\u=8.868 m/s[/tex]

puffs up because of aur traping in marshmallow

therefore A is the answer

thank you

Answer:

its hurricane

Explanation:

beacuse almost all the time hurricanes cause alot of trajectory in the compasses and weather maps

The study of weather patterns can predict the trajectory and intensity of hurricanes. So, option A.

The state of the atmosphere, which includes factors such as temperature, air pressure, wind, humidity, precipitation, and cloud cover, is referred to as the weather.

Here,

Weather condition is the local climate over a specific time period, which might range from one to several weeks. Meteorological conditions are those that are characteristic for a certain place or seasons.

The study of weather and atmospheric patterns across time is known as climatology. This branch of science is devoted to observing, examining, and comprehending global weather patterns, as well as the atmospheric circumstances that lead to them.

The atmosphere's current condition can be determined by combining data from weather stations, satellites, and even data collected by aircraft.

Following that, meteorologists use what they know about atmospheric processes to predict how the atmosphere will change, so altering the weather.

Hence,

The study of weather patterns can predict the trajectory and intensity of hurricanes. So, option A.

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Answer:

Current = dQ/dt

or I = dQ/dt

Where I represents current.

Which is the rate of flow of charge.

Q=4 + 2t + t²

dQ/dt = 2 + 2t --- This is the relation that gives the instantaneous current.

At time t=2sec

dQ/dt = I = 2 + 2t

= 2 + 2(2)

=2 + 4

= 6A.

Answer:

kdfihiyfxnlL chapter kar kaam

Explanation:

off influx teenon Palin

Answer:

Explanation:

Reverse the second equation, and change the sign of the enthalpy

what? Is there a picture you can show us with this question

Answer:

By the Pythagorean Theorem the distances from the speakers os

5 and 5.5 (rounding) meters   - let y be the wavelength in the solution

n y = 5      n is number of wavelengths from speaker

(n + m) y = 5.5      m must be integral for constructive interference

m y = .5       subtracting equations

m = 2      and y = ,25   for the above conditions

(n + 2) y = 5.5     substituting for m

n = 5.5 / .25 - 2 = 20

f = v / y     using frequency of sound

f = 340 / .25 = 1360 / sec    for lowest frequency

Check: D1 = y n  = ,25 * 20 = 5

and D2 = .25 * 22 = 5.5     for the distances traveled

Answer:

This Displacement Calculator finds the distance traveled or displacement (s) of an object using its initial velocity (u), acceleration (a), and time (t) traveled. The equation used is s = ut + ½at2; it is manipulated below to show how to solve for each individual vvariation

Answer:

B- the melting of polar ice caps

Explanation:

As the world's temperature increases, polar ice caps will no longer be able to remain solid.

Answer:

The second one says cant open file............

Answer:

a) the required time is 0.6283 μs

b) the inductor current is 0.5 mA

Explanation:

Given the data in the question;

The capacitor voltage has its maximum value of 25 V at t = 0

i.e V[tex]_m[/tex] = V₀ = 25 V

we determine the angular velocity;

ω = 1 / √( LC )

ω = 1 / √( ( 20 × 10⁻³ H ) × ( 8.0 × 10⁻¹² F) )

ω = 1 / √( 1.6 × 10⁻¹³  )

ω = 1 / 0.0000004

ω = 2.5 × 10⁶ s⁻¹

a) How much time does it take until the capacitor is fully discharged for the first time?

V[tex]_m[/tex] =  V₀sin( ωt )

we substitute

25V =  25V × sin( 2.5 × 10⁶ s⁻¹ × t )

25V =  25V × sin( 2.5 × 10⁶ s⁻¹ × t )

divide both sides by 25 V

sin( 2.5 × 10⁶ × t ) = 1

( 2.5 × 10⁶ × t ) = π/2

t = 1.570796 / (2.5 × 10⁶)

t = 0.6283 × 10⁻⁶ s

t = 0.6283 μs

Therefore, the required time is 0.6283 μs

b) What is the inductor current at that time?

[tex]I[/tex](t) = V₀√(C/L) sin(ωt)

{ sin(ωt) = 1 )

[tex]I[/tex](t) = V₀√(C/L)

we substitute

[tex]I[/tex](t) = 25V × √( ( 8.0 × 10⁻¹² F ) / ( 20 × 10⁻³ H ) )

[tex]I[/tex](t) = 25 × 0.00002

[tex]I[/tex](t) = 0.0005 A

[tex]I[/tex](t) = 0.5 mA

Therefore, the inductor current is 0.5 mA

The time taken for the capacitor to fully discharge is 6.28 x 10⁻⁷ s.

The current in the inductor at the given time is 0.0005 A.

The angular velocity of the circuit is calculated as follows;

[tex]\omega = \frac{1}{\sqrt{LC} } \\\\\omega = \frac{1}{\sqrt{20 \times 10^{-3} \times 8 \times 10^{-12} } } \\\\\omega = 2.5 \times 10^6 \ rad/s[/tex]

V = V₀(sinωt)

sinωt = V/V₀

sinωt = = 25/25

sin(ωt) = 1

ωt = sin⁻¹ (1)

ωt = π/2

2.5 x 10⁶ t = π/2

t = 1.57 / (2.5 × 10⁶)

t = 6.28 x 10⁻⁷ s

The current in the inductor at the given time is calculated as follows

[tex]I(t) = V_0 \sqrt{\frac{C}{L} } \\\\I = 25 \times \sqrt{\frac{8\times 10^{-12}}{20 \times 10^{-3}} } \\\\I = 0.0005 \ A[/tex]

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Answer:

The maximum amplitude power is 1.12 W

Explanation:

Given;

length of each side of the square, L = 18 cm = 0.18 m

angular frequency, f = 60 Hz

magnetic field, B = 0.3 T

resistance of the loop, R = 12 ohm

The area of the loop, A = L² = 0.18 m x 0.18 m = 0.0324 m²

The angular speed, ω = 2πf = 2π x 60 = rad/s = 377.04 rad/s

The maximum value of emf induced;

[tex]E_{max} = NBA \omega\\\\where; \\N \ is \ number \ of \ turns\\\\E_{max} = (1) \times 0.3 \times 0.0324 \times 377.04\\\\E_{max} = 3.665 \ V[/tex]

The maximum amplitude power is calculated as;

[tex]Power = \frac{(E_{max})^2 }{R} \\\\Power = \frac{(3.665)^2}{12} \\\\Power = 1.12 \ W[/tex]

Answer:

We want to solve the sum:

6.74*10⁴ + 8.95*10⁴

first, we take the common factor 10⁴ out, so we get:

(6.74 + 8.95)*10⁴

Now we solve the sum:

(15.66)*10⁴

Now we want to rewrite it in exponential form, wo we can rewrite it as:

(15.66)*10⁴ = (1.566*10)*10⁴ = (1.566)*10*10⁴ = (1.566)*10⁴⁺¹ = 1.566*10⁵

k = 5.

Answer:

the is metallurgy .....

Answer:

ans: 2250 meters

Explanation:

initial velocity (U)= 15 m/s

final velocity (V) = 0m/s , since need to come in rest

total time taken (T) = 5 min= 300 seconds

total distance covered (S)= UT + 1/2 aT^2 ,

a= acceleration

S= 15 × 300 + 0.5 ×(0 - 15) × 300

since a = (V - U)/ T

S = 4500 - 2250

S= 2250 m

Answer:

The maximum speed is 18.86 m/s.

Explanation:

initial  radius, r = 150 m

maximum speed, v = 26.5 m/s

new radius, r' = 76 m

Let the new maximum speed is v'.

The formula of the maximum speed is

[tex]tan\theta = \frac{v^2}{rg}[/tex]

So,

[tex]\frac{v'^2}{v^2}=\frac{r'}{r}\\\\\frac{v'^2}{26.5\times 26.5}=\frac{76}{150}\\\\v=18.86 m/s[/tex]