Select the correct answer.
If you increase the frequency of a sound wave four times, what will happen to its speed?
A.
The speed will increase four times.
B.
The speed will decrease four times.
C.
The speed will remain the same.
D.
The speed will increase twice.
E.
The speed will decrease twice.

Answer:

the mass of the box is 17 kg

Explanation:

Given;

magnitude of the force applied by the fisherman, F = 51 N

magnitude of acceleration of the box, a = 3 m/s²

the mass of the box is calculated using Newton's law of motion;

F = ma

where;

m is the mass of the box

m = F / a

m = (51) / (3)

m = 17 kg

Therefore, the mass of the box is 17 kg

Answer:

171.5 m

Explanation:

To find the distance, speed x time

342 x 0.5

171.5 m

Hope this helped!

Answer:

time is 32 s and speed is 304.3 m/s

Explanation:

Height, h = 146 m

speed, u = 14 m/s

Angle, A = 43 degree

Let it hits the ground after time t.

Use second equation of motion

[tex]h = u t +0.5 at^2\\\\- 146 =14 sin 43 t - 4.9 t^2\\\\4.9 t^2 - 9.5 t - 146 =0 \\\\t =\frac{9.5\pm\sqrt {90.25 + 2861.6}}{9.8}\\\\t=\frac{9.5\pm 54.3}{9.8}\\\\t = 32.05 s, - 22.4 s[/tex]

Time cannot be negative so the time is t = 32 s .

The vertical velocity at the time of strike is  

v' =  u sin A - g t

v' = 14 sin 43 - 9.8 x 32 = 9.5 - 313.6 = - 304.1 m/s

horizontal velocity

v'' = 14 cos 43 =10.3 m/s

The resultant velocity at the time of strike is

[tex]v=\sqrt{v'^2 + v''^2}\\\\v = \sqrt{304.1^2 +10.3^2 }\\\\v = 304.3 m/s[/tex]  

Answer:

0.3333

Explanation:

Acceleration = change in velocity/time

a = 20 m/s / 60 m/s

a = 0.3333 m/s^2

Answer:

3 years

Explanation:

Find the circumference of each orbit in AU.

2xπx1=6.283185307

2xπx3=18.84955592

Divide them.

18.84955592/6.283185307=3

3 years

Answer:

by the drag force, 2.4004512 × 10⁻⁵ J is added to the air.

Explanation:

Given the data in the question;

drag coefficient of Cd = 1.4

speed v = 6.0 m/s

One model expands to a square 1.8 mm on a side

Area A = 1.8 × 1.8 = 3.24 mm² = 3.24 × 10⁻⁶ m²

distance travelled s = 240 mm = 0.24 m

we know that; density of air e = 1.225 kg/m³

Now,

Dragging force F[tex]_D[/tex] = ( Cd × e × v² × A  ) / 2

thermal energy = F[tex]_D[/tex] × s

so

thermal energy = ( 1.4 × 1.225  × (6)² × (3.24 × 10⁻⁶) × 0.24  ) / 2

thermal energy = ( 4.8009024 × 10⁻⁵ ) / 2

thermal energy = 2.4004512 × 10⁻⁵ J

Therefore,  by the drag force, 2.4004512 × 10⁻⁵ J is added to the air.

Answer:

3.83×10¯⁴ N

Explanation:

From the question given above, the following data were obtained:

Charge 1 (q₁) = +2.4x10¯⁸ C

Charge 2 (q₂) = +1.8x10¯⁶ C

Distance apart (r) = 1.008 m

Electrical constant (K) = 9×10⁹ Nm²/C²

Force (F) =?

The magnitude of the electrical force acting between the two charges can be obtained as follow:

F = Kq₁q₂ / r²

F = 9×10⁹ × 2.4x10¯⁸ × 1.8x10¯⁶ / (1.008)²

F = 0.0003888 / 1.016064

F = 3.83×10¯⁴ N

Thus the magnitude of the electrical force acting between the two charges is 3.83×10¯⁴ N

Answer:

3.73 * 10^16   photons/sec

Explanation:

power supply = 3.0 V

Emits 440 nm blue light

current in LED = 11 mA

efficiency of LED = 51%

Calculate the number of photons per second the LED will emit

first step : calculate the energy of the Photon

E = hc / λ

   =(  6.62 * 10^-34 * 3 * 10^8 )  / 440 * 10^-9

   = 0.0451 * 10^-17  J

Next :

Number of Photon =( power supply * efficiency * current ) / energy of photon

= ( 3 * 0.51 * 11 * 10^-3 ) / 0.0451 * 10^-17

= 3.73 * 10^16 photons/sec

Answer:

The intensity of light passing from the third polarizer is 3Io/16.

Explanation:

The law of Malus is given by

[tex]I=I_o cos^2\theta[/tex]

Let the incident intensity of light is Io.

The intensity of light passing from the first polarizer is

[tex]I' = \frac{I_o}{2}[/tex]

The intensity of light passing from the second polarizer is

[tex]I''=\frac{I_o}{2}\times cos^230 =\frac{3I_o}{8}[/tex]

The intensity of light passing from the third polarizer is

[tex]I''' = \frac{3I_o}{8}\times cos^2 60\\\\\\I''' = \frac{3I_o}{16}[/tex]

Answer:

B. The Spring equinox

Explanation:

The vernal equinox marks the moment the sun crosses the celestial equator.  The vernal equinox happens on March 19, 20, or 21 every year in the Northern Hemisphere. In the Southern Hemisphere, this same event marks the beginning of fall.  (Source: What Exactly Is The Spring Equinox? - Dictionary.com)

Hopefully this helps.

Answer:

answer is 37 ohm since current e

remains same in series

Answer:

[tex]d=1.2m[/tex]

Explanation:

From the question we are told that:

Spring constant [tex]k= 4000 N/m[/tex]

Compressed [tex]l_d= 10cm=>0.10[/tex]

Mass [tex]m=1.0kg[/tex]

Length of horizontal section  [tex]l=5.0-m[/tex]

Coefficient of friction [tex]\mu=0.20[/tex]

Angle [tex]\theta=60 \textdegree[/tex]

Generally the equation for Kinetic Energy K.E is mathematically given by

 [tex]K.E=\mu mgL+mgdsin\theta[/tex]

 [tex]\frac{1}{2}k*l_d^2=\mu mgL+mgdsin\theta[/tex]

 [tex]\frac{1}{2}(4000)*0.1^2=0.2*1*9.8*5+1*9.8*d*sin60[/tex]

 [tex]d=1.2m[/tex]

Answer:

3.92N

Explanation:

Force= mass×accelerarion due gravity

But mass= 0.40kg

acceleration due to gravity = 9.8 m/s^2

Force = 0.40×9.8

Force=3.92N

Answer:

A

Explanation:

a pex

Answer:

Capacitance= 1.18×10^-6

Answer: 1.18*10^-6

Explanation:

Answer:

a) S =  63.2 km/h

b) V =  63.2 km/h*(-0.316 , 0.949)

Explanation:

Let's define:

North as the positive y-axis

East as the positive x-axis.

Also, remember the relation:

Distance = Time*Speed

Let's assume that she starts at the position (0km, 0km)

Then she travels due North at 90km/h for two hours, then the displacement is

90km/h*2h = 180km to the north

Then the new position is:

(0km, 180km)

Then she travels West at 60km/h for one hour.

Then the distance traveled to the West (negative x-axis) is:

60km/h*1h = 60km to the west

Then the new position is:

(-60km, 180km).

a) The average speed is defined as the quotient between the displacement and the time.

We know that the total time traveled is 3 hours.

And the displacement is the difference between the final position and the initial position.

this is:

D = √( -60km - 0km)^2 + (180km - 0km)^2)=

D = √( (60km)^2 + (180km)^2) = 189.7 km

Then the average speed is:

S = (189.7 km)/(3 h) = 63.2 km/h

b) Now we want to find the average velocity, this will be equal to the average speed times a versor that points from the origin to the direction of the final position.

So, if the final position is (-60km, 180km)

We need to find a vector that represents the same angle, but that is on the unit circle.

Then, if the module of the final position is 189.7 km (as we found above), then the versor is just given by:

(-60km/ 189.7 km, 180km/ 189.7 km)

(-60/189.7 , 180/189.7)

We can just check that the module of the above versor is 1.

[tex]module = \sqrt{(\frac{-60}{189.7} )^2 + (\frac{180}{189.7} )^2} = \frac{1}{189.7}* \sqrt{(-60 )^2 + (180 )^2} = 1[/tex]

Then the average velocity is:

V = 63.2 km/h*(-60/189.7 , 180/189.7)

We can simplify our versor so the velocity equation is easier to read:

V = 63.2 km/h*(-0.316 , 0.949)

Answer:

- increasing use of hybrid crops

- altering genes in DNA to create new plants

- developing disease or pest resistant crops

Explanation:

The use of genetic factors to influence the growth of a plant encompasses manipulating the genetic constituent (gene) of such plant.

For example,

- Increasing use of hybrid crops entails mating two pure bred plants based on a gene of interest responsible for a particular trait, to form a hybrid.

- Altering genes in DNA to create new plants is also a genetic factor as it has to with gene modification.

- developing disease or pest resistant crops means that the genetic make up of such plant has been modified to be resistant to pest/disease.

Answer:

Freezing Point - Lower

Boiling Point - Higher

Solid- liquid transition line in the phase diagram has a negative slope, but the liquid-gas transition line has a positive slope. Since there is more air pressure at 100m it will take less to freeze the water but more to boil it since it requires a larger temperature under larger pressures

Let v be the dog's initial velocity. Then

(13.5 m/s)^2 - v ^2 = 2 (1.50 m/s^2) (49.3 m)

==>   v ^2 = (13.5 m/s)^2 - 2 (1.50 m/s^2) (49.3 m)

==>   v = √((13.5 m/s)^2 - 2 (1.50 m/s^2) (49.3 m))

==>   v ≈ 5.86 m/s

Answer:

speeding up is the answer

Explanation:

from the graph it can be seen that as the time (horizontal axis) increases the speed of vehicle (vertical axis) increases

Answer:

[tex]\boxed {\boxed {\sf 40 \ kilograms}}[/tex]

Explanation:

Momentum is the product of velocity and mass. The formula is:

[tex]p=m*v[/tex]

We know the rock is falling. Its momentum is 200 kilograms meters per second and its velocity is 5 meters per second. Substitute the values into the formula.

[tex]200 \ kg \ m/s = m * 5.0 \ m/s[/tex]

We are solving for m, the mass. We must isolate the variable. It is being multiplied by 5 meters per second. The inverse of multiplication is division, so we divided both sides by 5.0 m/s.

[tex]\frac{200 \ kg \ m/s}{5.0 \ m/s}=\frac{ m* 5.0 \ m/s }{5.0 \ m/s}[/tex]

[tex]\frac{200 \ kg \ m/s}{5.0 \ m/s}=m[/tex]

The units of meters per second (m/s) cancel.

[tex]\frac{200 \ kg}{5.0 } =m[/tex]

[tex]40 \ kg = m[/tex]

The falling rock has a mass of 40 kilograms.

Answer:

c

Explanation:

in food and batteries chemical energy is stored :) hope this helped

Answer:

REVIEWS

Wing-Kuen Ling, in Nonlinear Digital Filters, 2007

Controllability and observability

For a continuous time system, assume that x(0) = 0. ∀x1, if ∃t1 > 0 and u(t) such that x(t1) = x1, then the continuous time system is said to be reachable. Similarly, for a discrete time system, assume that x(0) = 0. ∀x1, if ∃n1 > 0 and u(n) such that x(n1) = x1, then the discrete time system is said to be reachable. For a continuous time system, if ∀x0, x1, ∃t1 > 0 and u(t) such that x(0) = x0 and x(t1) = x1, then the continuous time system is said to be controllable. Similarly, for a discrete time system, if ∀x0, x1, ∃n1 > 0 and u(n) such that x(0) = x0 and x(n1 = x1, then the discrete time system is said to be controllable. For LTI systems, the set of reachable state is R(|BAB… AnB|), where R(A) is defined as the range of A, that is R(A) = {y : y = Ax}. Also, the LTI systems are controllable if and only if R(A) = Rn Or in other words, rank(|BAB… AnB|) = n.

Answer:

 v₂ /v₁ = 2.3 10⁺²

Explanation:

The energy is conserved so the total potential energy must be transformed into kinetic energy

          K = U

          ½ m v² = q ΔV

          v = [tex]\sqrt{\frac{2q \Delta V}{m} }[/tex]

a) Let's find the speed of the electron

           m = 9.1 10⁻³¹ kg

as they do not indicate the value of the power difference, we will assume that ΔV = 1 V is worth one

           v = [tex]\sqrt{ \frac{2 \ 1.6 \ 10^{-19} \ 1}{9.1 \ 10^{-31}} }[/tex]

           v = [tex]\sqrt {0.3516 \ 10^{12}}[/tex]

           v1 = 0.593 10⁶ m / s

b) the velocity of a hydrogen ion

            M = M_H + m

            M = 1.673 10⁻²⁷ + 9.1 10⁻³¹

            M = 1.67391 10⁻²⁷ kg

            M = 1.67 10⁻²⁷ kg

            v = [tex]\sqrt{ \frac { 2 \ 1.6 \ 10^{-19} \ 1}{1.67 \ 10^{-27}} }[/tex]

             v = [tex]\sqrt{ 1.916167 \ 10^8 }[/tex]

             v₂ = 1.38 10⁴ m / s

the relationship between these speeds is

           v₂ / v₁ = 1.38 10⁴ / 0.593 10⁶

           v₂ /v₁ = 2.3 10⁺²

Answer:

[tex]R _{t} = R _{0}( \alpha t + 1) \\ = 4 \times {10}^{ - 3} (3.9 \times {10}^{ - 3} \times 20 + 1) \\ = 4 \times {10}^{ - 3} (1.078) \\ = 4.312 \times {10}^{ - 3} \: Ω[/tex]

Answer:

Magnitude = 15.86 units

direction = 69 degree below negative X axis

Explanation:

A = 20 units at 60.0° counterclockwise from the negative x - axis

B = 40 units at 30.0° counterclockwise from the positive x - axis

C = 35 units at 60.0° clockwise from the negative y - axis

Write the vectors in the vector form

[tex]\overrightarrow{A} =20 (- cos 60 \widehat{i} - sin 60 \widehat{j})=- 10\widehat{i} - 17.3 \widehat{j}\\\\\overrightarrow{B} =40 (cos 30 \widehat{i} + sin 30 \widehat{j})= 34.6\widehat{i} +20 \widehat{j}\\\\\overrightarrow{C} =35 (- sin 60 \widehat{i} - cos 60 \widehat{j})=- 30.3\widehat{i} - 17.5 \widehat{j}\\\\Now\\\\overrightarrow{A} + \overrightarrow{B} + \overrightarrow{C} = (- 10 + 34.6 - 30.3) \widehat{i} + (-17.3 + 20-17.5)\widehat{j}\\\\[/tex]

[tex]\\\overrightarrow{A} + \overrightarrow{B} + \overrightarrow{C} = - 5.7\widehat{i} -14.8\widehat{j}[/tex]

The magnitude is given by

[tex]= \sqrt{5.7^2 + 14.8^2} = 15.86 units[/tex]

The direction is given by

[tex]tan\theta = \frac{- 14.8}{- 5.7}\\\\\theta= 69^o[/tex]

below negative X axis.  

Answer:

25

Explanation:

magnitude and (b) direction (as an angle relative to the x axis) of the velocity