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
Write any two uses of simple machines.
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
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
Gender differences in learning are due to both genetics and socialization.
t or f
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
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.
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?
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.
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
Answer:
has more energy, has a greater amplitude, has a higher frequency
Explanation:
2 ways in which the effects of friction can be minimised in the experiment
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
Explain how seafloor spreading is like a conveyor belt
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:
list and describe the units of power
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.
please help me on my physics hw
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
Blown balloon kept outside on a sunny day bursts what will happen to the ballon
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.
NO LINKS PLEASE. brainly to the best answer.
Compare and contrast potential energy and kinetic energy
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:
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
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.
Suppose you are working on green house, which light you would
use for their growth?
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.
at what point does the skater have the least amount of KE kinetic energy?
Answer:
I think it's D
Explanation:
because kinetic basically means moving and potential mean sitting still so ig it's c or D
What are two ways you can increase power by climbing the stairs?
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
timedistanceIf you don't like distance as an answer, you can carry something up the stairs -- anything that increases F will do.
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
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
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
Identify the different parts of the face
Answer:
head
four head
hair
eyes
ears
nose
lips
chick
chin
eyebrow
eyelid
Which scenario did not include a chemical change?
Answer:
what scenario i dont understand
Explanation:
step by step explenation
Which One don’t lie
Explanation:
heat but I dont see answer choices
Sounds that reflect off of hard surfaces can create an echo.
O True
O False
Answer: True
Explanation:
science help please in le photo...........
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
Answer:
C. Distance 90 feet Displacement 0 feet
is wooden blocks transparent,translucent or opaque
Answer:
opaque
Explanation:
Materials such as wood, stone, and metals are opaque to visible light.
a _____ has to do with the direction of a force
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
what is the difference between food and money?
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
Atruck with a mass of 5280 Kg has an acceleration of 45 m/s/s what is the force acting on the truck?
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?
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