the distance between a boy and a hill is 250 meters. if the boy shouts after how long will the echo be heard numerical problem​

Answers

Answer 1

Answer:

1.47 s

Explanation:

From the question,

s = 2d/t................... Equation 1

s = speed of sound in air, d = distance between the boy and the hill, t = time to hear the echo.

make t the subject of the equation

t = 2d/s............... Equation 2

Given: d = 250 meters

Constant: s = 340 m/s

Substitute these values into equation 2

t = (2×250)/340

t = 500/340

t = 1.47 s


Related Questions

When heat moves from the ocean to the surrounding air, which is this an example of?
A the transfer of energy from the atmosphere to the hydrosphere
B the transfer of energy from the hydrosphere to the atmosphere
C the transfer of matter from the atmosphere to the hydrosphere
D the transfer of matter from the hydrosphere to the atmosphere

Answers

B) The transfer of energy from the hydrosphere to the atmosphere

This is because oceans are part of the hydrosphere. As the air warms it flows up into the atmosphere.

Hope this helps!

please help me on my physics hw ​

Answers

Answer:

1. 11 A

2. 240 V

3. 8 Ω

4. 60 C

5. 14400 C

Explanation:

1. Determination of the current.

Voltage (V) = 110 V

Resistance (R) = 10 Ω

Current (I) =?

V = IR

110 = I × 10

Divide both side by 10

I = 110 / 10

I = 11 A

2. Determination of the voltage

Current (I) = 3 A

Resistance (R) = 80 Ω

Voltage (V) =?

V = IR

V = 3 × 80

V = 240 V

3. Determination of the resistance.

Current (I) = 0.5 A

Voltage (V) = 4 V

Resistance (R) =?

V = IR

4 = 0.5 × R

Divide both side by 0.5

R = 4 / 0.5

R = 8 Ω

4. Determination of the charge

Current (I) = 2 A

Time (t) = 30 s

Charge (Q) =?

Q = it

Q = 2 × 30

Q = 60 C

5. Determination of the charge.

We'll begin by converting 20 mins to seconds. This can be obtained as follow:

1 min = 60 s

Therefore,

20 mins = 20 × 60

20 mins = 1200 s

Finally, we shall determine the charge as follow:

Current (I) = 12 A

Time (t) = 1200 s

Charge (Q) =?

Q = it

Q = 12 × 1200

Q = 14400 C

Una caja con medicina es lanzada desde un avión localizado a una distancia vertical de 340 m por encima de un río. Si el avión lleva una velocidad horizontal de 70 m/s¿Qué distancia horizontal recorrerá la caja con medicina antes de caer al río?

Answers

Answer:

La distancia horizontal que recorrerá la caja con medicina antes de caer al río es 583.1 metros.

Explanation:

Una caja con medicina es lanzada desde un avión localizado a una distancia vertical de 340 m por encima de un río.  Este movimiento posee una composición en dos dimensiones: uno horizontal sin aceleración, y el otro vertical con aceleración constante debido a la gravedad.  Por lo que se trata de un movimiento rectilíneo uniforme (MRU) en su trayectoria horizontal o eje horizontal (es decir, su velocidad es constante) y un movimiento uniformemente variado (MRUV) en su trayectoria vertical o en el eje vertical (es decir, su aceleración es constante).

En este caso, son conocidos los datos, considerando el sistema de referencia de la imagen:

Vy = 0 m/s (trayectoria vertical) Vx = 70m/s (velocidad horizontal)  hi = 340 m (altura inicial) g = -9,8 m/s² hf = 0 m (altura final. Cuando la caja de medicina cae al río, su altura será 0 m)

En el caso del MRUV, la posición puede calcularse mediante la expresión:

Posición final= Posición inicial + Velocidad inicial*t + [tex]\frac{1}{2}[/tex]*a*t²

donde a es la aceleración y t el tiempo transcurrido.

En este caso, reemplazando los datos conocidos, teniendo en cuenta que el MRUV sucede en la trayectoria vertical y que la aceleración es el valor de la gravedad:

0 m= 340 m + 0 m/s*t + [tex]\frac{1}{2}[/tex]* (-9.8 m/s²)* t²

Resolviendo:

-340 m= [tex]\frac{1}{2}[/tex]* (-9.8 m/s²)* t²

[tex]\frac{-340 m}{\frac{1}{2} *(9.8\frac{m}{s^{2} } )} =t^{2}[/tex]

69.39 s²= t²

t= √69.39 s²

t= 8.33 s

La posición en MRU se obtiene mediante:

Posición final= Posición inicial + velocidad* tiempo

Con los datos conocidos y el tiempo calculado previamente, es posible calcular la distancia horizontal que recorrerá la caja con medicina antes de caer al río, siendo la posición inicial en x igual a cero:

Posición final= 0 m + 70m/s* 8.33 s

Posición final= 583.1 m

La distancia horizontal que recorrerá la caja con medicina antes de caer al río es 583.1 metros.

Veremos que la distancia horizontal que recorre la caja es 583.1 metros.

¿Como encontrar la distanca horizontal recorrida?

Recordar que la velocidad vertical y horizontal son independientes.

Aqui, lo primero que debemos hacer es encontrar el tiempo que la caja tarda en llegar al suelo.

Para ello usamos la ecuación de movimiento vertical:

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

Donde el primer termino representa la gravedad, el segundo la velocidad inicial (que es cero en este caso) y el tercero la altura inicial, que es 340m.

p(t) = (-4.9 m/s^2)*t^2 + 340m

La caja llegara al suelo cuando la función de arriba sea igual a cero:

(-4.9 m/s^2)*t^2 + 340m = 0

t = √(340m/(4.9 m/s^2)) = 8.33 s

Es decir, la caja tarda 8.33 segundos en llegar al suelo.

Esto significa que la caja se va a mover horizontalmente durante 8.33 segundos con una velocidad de 70m/s (la que tenía el avion). Es decir, la distancia horizontal que se mueve la caja es :

D = 8.33s*(70m/s) = 583.1 m

Sí quieres aprender más sobre ecuaciones de movimiento, puedes leer:

https://brainly.com/question/25316464

is wooden blocks transparent,translucent or opaque ​

Answers

Answer:

opaque

Explanation:

Materials such as wood, stone, and metals are opaque to visible light.

the soft ballplayer does 9876 joules of work when hitting a ball into center field. Assuming the ball landed 100 meters away from home plate, how much force did the player use to hit the ball?

Answers

Answer:

F = 987600 N

Explanation:

Force Equation

F=ma

Newton's second law states that force is proportional to what is required for an object of constant mass to change its velocity. This is equal to that object's mass multiplied by its acceleration. We use Newtons, kilograms, and meters per second squared as our default units, although any appropriate units for mass (grams, ounces, etc.) or velocity (miles per hour per second, millimeters per second2, etc.) could certainly be used as well - the calculation is the same regardless.

Solve

F = m * a

F = 100 kg * 9876 m/s2

F = 987600 N

Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.

Which scenario did not include a chemical change?

Answers

Answer:

what scenario i dont understand

Explanation:

step by step explenation

Suppose you are working on green house, which light you would
use for their growth?

Answers

Answer:

Fluorescent lighting is usually used.

Explanation:

Answer:

HPS lighting or LED light

Explanation:

HPS light is well known choice with a proven track record for growers. While you can also use LED lights as an alternative to incandescent or HPS fixtures for day length extension.

The lettuce is scattered all over the garden.
Travel down each path until you reach a head of lettuce, then continue to pick it while
there is still some left.
This is vety hard this is level 4 number 10 on code.org plsss help me

Answers

Answer:

Explanation:

Coding is all about logic, since I do not have the actual problem from the website I will guide you on how to solve this.

Since you need to go a certain direction you will need to indicate to the character which direction to go. Next, we need to prevent the player from travelling through a wall, we can accomplish this using an IF/ELSE statement. IF the next block in that direction is a wall then do not move forward, ELSE move forward. We would call this statement every time the player tries to move in any direction. Finally, once we reach the lettuce we need to continue picking it until there is no more. To do this we use a While loop, that checks to see if there is any more lettuce, if there is it will run the code to pick up lettuce, if there is NO more then the While loop will exit. That would be the entire code.

Identify the different parts of the face ​

Answers

Answer:

head

four head

hair

eyes

ears

nose

lips

chick

chin

eyebrow

eyelid

Atruck with a mass of 5280 Kg has an acceleration of 45 m/s/s what is the force acting on the truck?

Answers

117.3 I think that’s it mb if that wrong

Gender differences in learning are due to both genetics and socialization.

t or f

Answers

Answer:

TRUE

Explanation:

THERE YOU GOOO!!!!!!!!!!!!!!

(also hi lulu)

one end of a horizontal spring(k=80N/m)is held fixed while an external force is applied to the free end,stretching it slowly from×1=o to ×2=4cm.what is work done by the applied force on the spring​

Answers

Answer:

6.4 Joules

Explanation:

For springs, Hooke's law states that;

F = ke

where F is a force applied, e is the extension and k is the spring constant.

Work done in a spring is the same as the potential energy stored in the spring. So that;

Work done = [tex]\frac{1}{2}[/tex] k[tex]e^{2}[/tex]

e = [tex]x_{2}[/tex] - [tex]x_{1}[/tex]

[tex]x_{2}[/tex] = 4 cm = 0.4 m

[tex]x_{1}[/tex] = 0

So that,

[tex]x_{2}[/tex] - [tex]x_{1}[/tex] = 0.4 m

Thus,

Work done = [tex]\frac{1}{2}[/tex] x 80 x [tex](0.4)^{2}[/tex]

                   = 40 x 0.16

                   = 6.4

Work done = 6.4 J

The work done by the force on the spring is 6.4 Joules.

Sounds that reflect off of hard surfaces can create an echo.
O True
O False

Answers

Answer: True

Explanation:

PLEASE HELP ASAP

Compare the two waves. Wave A ___ (check all that apply)





Group of answer choices

has more energy

has a greater amplitude

has a lower amplitude

has a higher frequency

has less energy

has a lower frequency

Answers

Answer:

has more energy, has a greater amplitude, has a higher frequency

Explanation:

More energy, has a great amplitude, and lastly has a higher frequency, hope this helps! Mark brainly pls!

What are two ways you can increase power by climbing the stairs?

Answers

Answer:

change the

timedistance force.

Explanation:

P = W/time

W = F*d

You have control over how fast you go up the stairs.

You also have control over how far up the stairs you go.

Therefore the answer is

timedistance

If you don't like distance as an answer, you can carry something up the stairs -- anything that increases F will do.

Imani stirs a cup of hot sencha tea with a cool silver spoon. She notices that the silver spoon becomes warmer. What energy change occurs when the silver spoon is added to the hot cup of sencha tea?

A. The spoon adds its cold to the hot tea

B. The hot tea absorbs the heat from the spoon

C. The cool spoon causes the water to expand thus cooling it

D. The tea loses heat to the spoon causing the spoon to become warmer

Answers

Answer:

D. The tea loses heat to the spoon causing the spoon to become warmer

Explanation:

When the silver spoon at a lower temperature than the tea, is added to the tea, it makes thermal contact. Hence, the heat transfer starts between the two until the equilibrium is reached. We know that the heat transfer takes place from the body with a higher temperature to a body with a lower temperature. As a result, the body with higher temperature loses heat and its temperature lowers down. While the body with a lower temperature gains heat and its temperature rises.

Therefore, the correct option is:

D. The tea loses heat to the spoon causing the spoon to become warmer

what is the difference between food and money?​

Answers

Food is edible and money isn’t you can buy stuff with money but you can’t buy stuff with food. Food and money have many differences. They are nothing close to similar.

Which One don’t lie

Answers

Explanation:

heat but I dont see answer choices

Write any two uses of simple machines.

Answers

Simple machines could be used to reduce effort or extend the ability of people to perform tasks beyond their normal capabilities.
Examples include pulley, lever, and incline plane

2 ways in which the effects of friction can be minimised in the experiment​

Answers

Answer:

Friction can be minimized by using lubricants like oil and grease and by using ball bearing between machine parts. A substance that is introduced between two surfaces in contact, to reduce friction, is called a lubricant. Fluid friction can be minimized by giving suitable shapes to the objects moving in the fluids.

Explanation:

hope it helps

Blown balloon kept outside on a sunny day bursts what will happen to the ballon​

Answers

When the balloon is kept in the sun, due to Sun's heat, the kinetic energy of gaseous particles inside the balloons also gets increased and the balloon expands. This will increase the pressure on the walls of the balloon. It continues to expand and comes to a stage when the baloon bursts.

science help please in le photo...........​

Answers

It’s the first one I think I hope is right if not sorry but I’m pretty sure it’s the First one ☝

Explain how seafloor spreading is like a conveyor belt

Answers

Answer:

In sea-floor spreading, the sea floor spreads apart along both sides of a mid-ocean ridge as new crst is added. As a result, the ocean floors move like conveyor belts, carrying the continents along with them.

Explanation:

NO LINKS PLEASE. brainly to the best answer.
Compare and contrast potential energy and kinetic energy​

Answers

Answer:

Kinetic energy is energy possessed by a body by virtue of its movement. Potential energy is the energy possessed by a body by virtue of its position or state. While kinetic energy of an object is relative to the state of other objects in its environment, potential energy is completely independent of its environment.

Both energies are related to motion.

Explanation:

list and describe the units of power​

Answers

Answer:

On the other hand, power is a scalar quantity and is basically the amount of energy consumed per unit time which has no direction.

Horsepower HP 746 watts

Kilowatts kW 1×103W

Megawatts MW 1×106W

Gigawatts GW 1×109W

The S.I unit of power is Watt(W) which is joule per second.

a _____ has to do with the direction of a force​

Answers

Answer:

The "solid force"? ... The direction of the force always seems to be coming out of the solid surface. A direction which is perpendicular to the plane of a surface is said to be normal. The force that a solid surface exerts on anything in the normal direction is called the normal force.

Explanation:

i think i hope this helps

In science, work is defined as the action that results when a force causes an object to move in the direction of the force. ... The object moves as a force is applied. The direction of the object's motion is the same as the direction of the force applied.

Question 4
1 pts
If you have a voltage of 120 volts entering your house and a light bulb with
0.625 amperes flowing through it, how many watts is your light bulb?
A. 50 watts
B. 150 watts
C. 25 watts
D. 75 watts

Answers

Answer:

D. 75 watts

Explanation:

brainliest please? i've just answered 3 of your questions and they were all correct! :) i hope i helped!

Answer:

(D) =75 WATTS

Explanation:

p(power)=i(current)×v(voltage)

p = 0.625 × 120

p =75 watts

CAN U HELP PLZZ? ;(
A 12kg aluminum box is sliding along a horizontal steel surface while experiencing a rightward applied force of 60N. The box has a displacement of 20m. Is this box in Equilibrium? *

A.)Yes, because the net force & net work is more than 0N
B.)Yes, because the net force & net work equals 0N
C.)No, because the net force & net work is more than 0N
D.)No, because the net force & net work equals 0N
E.)Need more info

Answers

Answer would be D sorry if wrong

at what point does the skater have the least amount of KE kinetic energy?

Answers

Answer:

I think it's D

Explanation:

because kinetic basically means moving and potential mean sitting still so ig it's c or D

You are playing baseball and hit a single, running to first base. Your distance and displacement are

Answer choices:
A. Both 90 feet

B. Both 0 feet

C. Distance 90 feet Displacement 0 feet

D. Distance 0 feet Displacement 90 feet

Answers

Answer:

C. Distance 90 feet Displacement 0 feet

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