An ultrasonic tape measure uses frequencies above 20 MHz todetermine dimensions of structures such as buildings. It does so byemitting a pulse of ultrasound into air and then measuring the timeinterval for an echo to return from a reflecting surface whosedistance away is to be measured. The distance is displayed as adigital read-out. A tape measure emits a pulse of ultrasound with afrequency of 25.0 MHz.
(a) What is the distance to an object fromwhich the echo pulse returns after 24ms when the air temperature is 26°C?
(b) What should be the duration of the emitted pulse if it is toinclude 10 cycles of the ultrasonic wave?
(c) What is the spatial length of such a pulse?

Answers

Answer 1

Answer:  

a) 1m

b) 2μs

c) 3mm

Explanation:


Related Questions

A ball is attached to one end of a wire, the other end being fastened to the ceiling. The wire is held horizontal, and the ball is released from rest. It swings downward and strikes a block initially at rest on a horizontal frictionless surface. Air resistance is negligible, and the collision is elastic. The masses of the ball and block are, respectively, 1.48 kg and 2.77 kg, and the length of the wire is 1.11 m. Find the velocity of the ball just after the collision.

Answers

Answer: Velocity of the ball just after the collision is -1.414 m/s.

Explanation:

As energy is conserved in a reaction so here, energy before collision will be equal to the energy after collision.

[tex]E_{before} = mgh = E_{after} = \frac{1}{2}mv_{o}^{2}[/tex]

where,

m = mass

g = gravitational energy = [tex]9.8 m/s^{2}[/tex]

h = height or length

[tex]v_{o}[/tex] = initial velocity

Also here, height is the length of wire. Let the height be denoted by 'L'. Therefore,

[tex]\frac{1}{2}mv_{o}^{2} = mgL\\v_{o}^{2} = 2gL\\v_{o} = \sqrt{2gL}\\= \sqrt{2 \times 9.8 m/s^{2} \times 1.11 m}\\= 4.66 m/s[/tex]

Formula used to calculate velocity after the collision is as follows.

[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}][/tex]

where,

[tex]v_{f ball}[/tex] = final velocity of ball after collision

[tex]m_{ball}[/tex] = masses of ball

[tex]m_{block}[/tex] = masses of block

Substitute the values into above formula as follows.

[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}]\\= 4.66 m/s [\frac{1.48 kg - 2.77 kg}{1.48 kg + 2.77 kg}]\\= 4.66 m/s \times (-0.303)\\= -1.414 m/s[/tex]

Thus, we can conclude that velocity of the ball just after the collision is -1.414 m/s.

whem completing an emergency Roaside stop,it is necessary to put on your parking brake
A. True
B. False​

Answers

Answer:

trueeeeeeee..........mmmm...........

describe brefly how you can charge a body​

Answers

Answer:

charge or change?

Explanation:

I'll write my answer in the comments when you reply

How much work will a 500 watt motor do in 10 seconds?

Answers

Answer:

50j

Explanation:

Watts are units used to measure power. power can be defined as rate of energy transfer

500 watts means - 500 J of energy per second

in 1 second - 500 J of work is done

therefore within 10 seconds - 500 J/s x 10 s = 5000 J

work of 5000 J is carried out in 10 seconds

Answer:

Watts are units used to measure power. power can be defined as rate of energy transfer

500 watts means - 500 J of energy per second

in 1 second - 500 J of work is done

therefore within 10 seconds - 500 J/s x 10 s = 5000 J

work of 5000 J is carried out in 10 seconds

Explanation:

g An airplane is flying through a thundercloud at a height of 1500 m. (This is a very dangerous thing to do because of updrafts, turbulence, and the possibility of electric discharge.) If a charge concentration of 25.0 C is above the plane at a height of 3000 m within the cloud and a charge concentration of -40.0 C is at height 850 m, what is the electric field at the aircraft

Answers

Answer:

[tex]523269.9\ \text{N/m}[/tex]

Explanation:

q = Charge

r = Distance

[tex]q_1=25\ \text{C}[/tex]

[tex]r_1=3000\ \text{m}[/tex]

[tex]q_2=40\ \text{C}[/tex]

[tex]r_2=850\ \text{m}[/tex]

The electric field is given by

[tex]E=E_1+E_1\\\Rightarrow E=k(\dfrac{q_1}{r_1^2}+\dfrac{q_2}{r_2^2})\\\Rightarrow E=9\times 10^9\times (\dfrac{25}{3000^2}+\dfrac{40}{850^2})\\\Rightarrow E=523269.9\ \text{N/m}[/tex]

The electric field at the aircraft is [tex]523269.9\ \text{N/m}[/tex]

What does the Curl-up test assess?
O A.
Body composition
ОВ.
Muscular strength and endurance
O C. Flexibility
D.
Cardiovascular fitness

HURRRY
(it’s pe not physics)

Answers

muscular strength and endurance!

Answer:

assesses C.) muscular endurance

Explanation:

the pygmy shrew has an average mass of 2.0 g if 49 of these shrew are placed on a spring scale with a spring constant of 24 N/m , what is the springs displacement

Answers

Answer:

Spring's displacement, x = -0.04 meters.

Explanation:

Let the spring's displacement be x.

Given the following data;

Mass of each shrew, m = 2.0 g to kilograms = 2/1000 = 0.002 kg

Number of shrews, n = 49

Spring constant, k = 24 N/m

We know that acceleration due to gravity, g is equal to 9.8 m/s².

To find the spring's displacement;

At equilibrium position:

Fnet = Felastic + Fg = 0

But, Felastic = -kx

Total mass, Mt = nm

Fg = -Mt = -nmg

-kx -nmg = 0

Rearranging, we have;

kx = -nmg

Making x the subject of formula, we have;

[tex] x = \frac {-nmg}{k} [/tex]

Substituting into the formula, we have;

[tex] x = \frac {-49*0.002*9.8}{24} [/tex]

[tex] x = \frac {-0.9604}{24} [/tex]

x = -0.04 m

Therefore, the spring's displacement is -0.04 meters.

A radioactive material produces 1160 decays per minute at one time, and 4.0 h later produces 170 decays per minute. whats the half life

Answers

Answer:

Half life is 3.23 hours

Explanation:

Given

Decay rate at starting = 1160 decays per minute

Decay rate after 4 hours = 170 decays per minute

As we know know

[tex]N = N_0 *e ^{\Lambda *T}[/tex]

Substituting the given values, we get -

[tex]170 = 1160 *e ^{-4*\Lambda}\\0.1465 = e ^{-4*\Lambda}\\-0.834 = -4 * \Lambda\\\Lambda = 0.834/4\\\Lambda = 0.2085[/tex]

Also

[tex]t_{1/2} = \frac{ln2}{\Lambda}[/tex]

Substituting the given values we get -

[tex]t_{1/2} = =0.693/0.2085\\= 3.23[/tex]hours

If the acceleration of the body is towards the center, what is the direction of the unbalanced force ? Using a complete sentence , describe the direction of the net force that causes the body to travel in a circle at a constant speed.

Answers

Accelerating objects are changing their velocity. Velocity is often thought of as an object's speed with a direction. Thus, objects which are accelerating are either changing their speed or changing their direction. They are either speeding up, slowing down or changing directions. Changing the velocity in any one of these three ways would be an example of an accelerated motion.

An ideal horizontal spring-mass system has a mass of 1.0 kg and a spring with constant 78 N/m. It oscillates with a period of 0.71 seconds. When this same spring-mass system oscillates vertically instead, the period is _______ seconds. Enter 2 significant figures (a total of three digits) and use g = 10.0 m/s2 if necessary.

Answers

Answer:

T = 0.71 seconds

Explanation:

Given data:

mass m = 1Kg, spring constant K = 78 N/m, time period of oscillation T = 0.71 seconds.

We have to calculate time period when this same spring-mass system oscillates vertically.

As we know

[tex]T = 2\pi \sqrt{\frac{m}{K} }[/tex]

This relation of time period is true under every orientation of the spring-mass system, whether horizontal, vertical, angled or inclined. Therefore, time period of the same spring-mass system oscillating  vertically too remains the same.

Therefore, T = 0.71 seconds

Application question: In Lancaster county, Pennsylvania, it is common for members of the Amish community to use windmills to pump water from underground to fill a tank for drinking water. The wind causes the turbine blades to spin, rotating a shaft, which is transferred through some gears to operate a pump, which pumps water up from deep below the ground to fill an above ground tank. Identify the energy conversions happening at each step below.
Wind blows______causing the turbine to turn, rotating shaft works pump_____energy.
Motion of water moving up from well______energy.
Water in tank which is positioned 5 feet above the ground level______potential energy.

Answers

Answer:

Wind blows__wind energy ____causing the turbine to turn, rotating shaft works pump__mechanical___energy.

Motion of water moving up from well___kinetic energy___energy.

Water in tank which is positioned 5 feet above the ground level______potential energy

Explanation:

Wind has in it wind energy which is then used to rotate the turbine shaft which is a form of mechanical work and hence possess mechanical energy

Moving water posses kinetic energy and when this water is kept at some height it possess potential energy

An object changes velocity from 100m/s
to 76m/s in 6 seconds. If it has a mass of
20kg, what is the net force?

Answers

Answer:

1-1=0

Explanation:

ahriqqwertyuioo

Can someone take there time and answer this :)

Answers

Answer: I think B.)

Explanation:

the answer is D, because if there are the exact same organisms that are extinct in these two places, that means that they must have started at a similar place that no longer is connected.

The universe cooled after the Big Bang.At some point hydrogen atoms combined to form helium.What is this process called?

Answers

Answer:

Nuclear fusion

Explanation:

an object is moving at 60m/s and has a mass of 5 kg what is its momentum​

Answers

Answer:

300

Explanation:

the momentum is 300

p=mv

p=5×60

5×60 =300

What is the magnitude of the gravitational force acting on a
1.0 kg object which is 1.0 m from another 1.0 kg object?

Answers

Ans[tex]^{}[/tex]wer and expl[tex]^{}[/tex]anation is in a fi[tex]^{}[/tex]le. Li[tex]^{}[/tex]nk below! Go[tex]^{}[/tex]od luck!  

bit.[tex]^{}[/tex]ly/3a8Nt8n

An object is pushed with a force of 400 N for 20 meters; what is the work done on the object? Solve using W=F*d

Answers

Answer:

800joules

Explanation:

work is measured in joules

What are the similarities between a resultant force equilibrant force?

Answers

Answer:

Explanation:

Resultant is a single force that can replace the effect of a number of forces. "Equilibrant" is a force that is exactly opposite to a resultant. Equilibrant and resultant have equal magnitudes but opposite directions.

A doorknob is a type of wheel and axle. In a doorknob, the door handle acts as the wheel. The handle is connected to a cylinder, called a spindle, which acts as the axle. When the handle turns, the spindle turns in the same direction. The spindle is located inside the handle and pulls the latch back and forth, allowing the door to open.


In the doorknob shown above, when the handle is rotated a distance of 84 millimeters, the spindle is rotated a distance of 14 millimeters. What is the mechanical advantage of this doorknob?
A. 504
B. 6
C. 84
D. 14

Answers

I’m not 100% sure but I believe it’s C.84

A geologist notices that a river is eroding its valley at a constant rate. Knowing the height of the valley walls, how could the geologist figure out when the river started carving the valley?
A.
Count growth rings of trees growing on the valley floor.
B.
Divide the height of the valley walls by the rate of erosion.
C.
Fill up the river valley with rocks, and time how long it takes the rocks to wash out.
D.
Sit and observe the river for a few hours until the valley walls double in height.

Answers

Answer:

B.

Divide the height of the valley walls by the rate of erosion.

Explanation:

There is a relationship between the rate of erosion and the hieght at which it is eroded according to Newton's law of motion. In the case of the scenario above, the best way to determine the time the river started carving the valley would be the division of the height of the valley walls by the rate of erosion.

What happens when Earth rotates on its axis and how long does it take

Answers

Answer:

You get Day and Night

It takes 24 hour

Answer:

Explanation:

The Earth's orbit makes a circle around the sun. At the same time the Earth orbits around the sun, it also spins.Since the Earth orbits the sun and rotates on its axis at the same time we experience seasons, day and night, and changing shadows throughout the day.It only takes 23 hours, 56 minutes and 4.0916 seconds for the Earth to turn once on its axis.

When two substances that cannot dissolve each other are mixed, a ________ mixture is formed

Answers

Answer: hetero i think i dont know

Explanation:

Answer:

When two substances that cannot dissolve each other are mixed, a mixture is formed.

i hope this helps a little bit.

Classify each change (which can be manipulated within the green box) according to its effect on the wavelength.

a. Decrease frequency
b. Decrease damping
c. Decrease amplitude
d. Increase frequency
e. Increase amplitude
f. Increase damping
g. Shortens wavelength

Answers

Answer:

Explanation:

The classification will be made into 3 categories, which are

Ones that shortens wavelengths

Ones that lengthens wavelengths

Ones that has no effect on wavelengths

Shortens wavelengths -> Increase frequency

Lengthens wavelengths -> Decrease frequency

No effect -> Increase amplitude, decrease amplitude, increase damping, decrease damping.

Which statement best explains why objects are pulled toward Earth’s center?

Answers

Answer:

Earth has a much greater mass than objects on its surface

Planet X has a moon similar to Earth’s moon.

Which path would this moon’s orbit take?

Answers

what are the choices?

mdjxjxjcjfkfjjdksklqlakzjxjxkkskakMmznxkxkdkd?​

Answers

Answer:

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

I hope this helped!+*

Carbon-14 is the typical radioisotope used to date materials; however, it has a limitation to 40,000 years. A scientist who wants to date materials older than 40,000 years would most likely use which radioisotope?

Answers

Answer:

the decay of uranium ending in lead,  of potassium (40K) that becomes argon,  the decay of rubidium

Explanation:

For the radioactive dating process, a material is needed that has a known average life time and that we can know the amount of material at a given moment,

In the case of carbon 14 (14C), living beings stop capturing it from the air and plants when they die, so knowing the amount they currently have, it is possible to calculate the time in which they stopped absorbing, but the life time average is 5730 years, the maximum time that can be used is up to about 10 average visa times

To analyze extra samples have high half-life times

* the decay of uranium ending in lead

* the decay of potassium (40K) that becomes argon T1 / 2 = 1,251 10⁹ years

* the decay of rubidium (87Ru) which becomes strontium T1 / 2 = 4.92 10¹⁰ years

Question 2 of 20 :
Select the best answer for the question.
2. Which of the following is considered to be a vector?
A. Velocity
B. Time
C. Temperature
D. Mass
Mark for review (Will be highlighted on the review page)

Answers

The answer is A. velocity .

Velocity is a vector quantity because it need magnitude as well as direction to be defined.

A rabbit dashes across a field in a zig-zag pattern trying to outrun a fox. If the rabbit’s average is speed is 9.8 m/s it reaches the hole in 8.5 s what is the total distance it ran?

Answers

Answer:

83.3 m

Explanation:

From the question,

Applying on of the formula of velocity

V = d/t.................. Equation 1

Where V = average velocity, d = distance, t = time.

make d the subject of the equation

d = V×t................. Equation 2

Given: V = 9.8 m/s, t = 8.5 s

Substitute these values into equation 2

d = 9.8×8.5

d = 83.3 m

Hence the total distance covered by the rabbit is 83.3 m

Scientists are constantly exploring the universe, looking for new planets that support life similar to the life on
Earth. A new planet that supports life would have all of the following characteristics except -
A. a gaseous atmosphere.
B. an orbiting moon.
C. liquid water.
D. protection from radiation.

Answers

The answer would be “B” because humans would need water, protection from radiation so we don’t melt or burn to death lol, and a gaseous atmosphere because we would need oxygen.

A new planet that supports life would have all the following characteristics except an orbiting moon. Hence, option B is correct.

What is a Planet?

An enormous, spherical celestial object known as a planet is neither a star nor its remains. The nebular hypothesis, which states how an interstellar cloud falls out of a nebula to produce a young protostar encircled by a protoplanetary disk, is now the best explanation for planet formation.

By gradually accumulating material under the influence of gravity, or accretion, planets develop in this disk.

The rocky planets Mercury, Venus, Earth, and Mars, as well as the giant planets Jupiter, Saturn, Uranus, and Neptune, make up the Solar System's minimum number of eight planets. These planets all revolve around axes that are inclined relative to their respective polar axes.

To know more about Planet:

https://brainly.com/question/14581221

#SPJ2

Other Questions
*will give brainliest to first real answer*In two to three sentences, explain how transition words function like bridges. Can someone please help me I will mark u brilliant Solve for x.2x2 + x = 10 An agricultural scientist collected data to study the relationship between the amount of nitrogen added to a cornfield and the number ofbushels of corn produced. This is the regression line of the data, where y is measured in bushels of corn and x is measured in pounds ofnitrogen.y = 0.43x + 28.5What is the meaning of the slope of the regression line?O A. For every 0.43 pounds of nitrogen added to the field, the amount of corn yielded increases by 28.5 bushels.OB. For every 1 pound of nitrogen added to the field, the amount of corn yielded increases by 0.43 bushels.-OC. For every 1 pound of nitrogen added to the field, the amount of corn yielded increases by 28.5 bushels.OD. For every 28.5 pounds of nitrogen added to the field, the amount of corn yielded increases by 0.43 bushels. Match the following three scenarios. Are the equations Always True, Never True, or Sometimes True? How did the Mongol Empire destroy states and increase the interconnection of Afroeurasia? answer Please answer I really need help due at 11:50 18) Which BEST defines "countenance as it is used in paragraph 2?After this, the sacred Tmolus turns his face towards the countenance ofApollo; his words follow the direction of his face.A)Stringed musical instrumentsB)A sacred oath or commitment to serviceAttire or outer clothing worn by one in powerD)A person's face; appearance or facial expression ggghhhhhhhhhhhhjujjj i neeeeee helpppp asappppppp PLZZZZZ! HELP! I'll give brainliest to the first correct answer, five stars, and a heart! What is the area of this kite? A) 20 square meters B) 36 square meters C)40 square meters D) 80 square meters Please help me anyone ????!!!! ASAP pls 4^?=1024? i know the answer is 5 but is there an easier way to find that out instead of guessing? Create an equivalent ratio to 30:40 by dividing both sides by 10. What is the equivalent ratio? 5.0 g of copper was heated from 20C to 80C. How much energy was used to heat Cu? Write complete sentences, using the appropriate indirect object pronouns and singular formal (Ud.) commands.1. decir (Ud.)/ al Sr. Martnez / cmo llegar a la frutera2. ensear (Ud.) / a los Sres. Daz / dnde est la joyera3. escoger (Ud.) / a l / una florera buena4. traer (Ud.) / a m / un mapa del Distrito Federal5. buscar (Ud.) / a Rosa / unos regalos6. conseguir (Ud.) / a Lupe y Luis /direcciones al almacn7. comprar (Ud.) / a nosotros / unos dulces8. dar (Ud.) / a Ramn / dos monedas 8X=35WHAT IS THE VALUE FOR X THAT MAKES THE EQUATION TRUE? Use the picture below and determine which of the lines or line segments 20 pointsis/are a diametermAVELine mLine Segment BC Line Sesnent AB or ACLine Segment DELine 1 What role do cottage industries play in India's economy?