Answer:
YES
Explanation:
An echo may be defined as a sound which is repeated because of the sound waves that are produced are reflected back after striking a surface. Sound waves can smoothly bounce off the hard objects in the same manner as a rubber ball bounces back the ground.
When a sound wave strikes a hard surface, the sound waves gets reflected back and bounces back to the observer and produces an echo. If the sound waves strikes a soft surface it absorbs the sound.
Although the direction of a sound changes but the echo sounds in the same way as the original sound.
Based on the article "Will the real atomic model please stand up?,” describe what Dalton’s theory states about a molecule of water.
Answer:
Dalton’s theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.
Explanation:
Answer:
Sample Response: Dalton’s theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.
Explanation:
its literally the sample response
help me whenever possible.
Answer:
7. Option D. 8.4×10¯⁴ m/s North.
8. Option B. 2 m/s
Explanation:
7. Determination of the speed of the snail.
The following data were obtained from the question:
Distance travalled (d) = 15 m
Time (t) = 300 mins
Speed (S) =?
Next, we shall convert 300 mins to secs. This can be obtained as follow:
1 min = 60 secs
Therefore,
300 mins = 300 × 60 = 18000 secs
Finally, we shall determine the speed of the snail as follow:
Distance travalled (d) = 15 m
Time (t) = 18000 secs
Speed (S) =?
Speed = Distance travelled /time
Speed = 15 / 18000
Speed = 8.3×10¯⁴ m/s
Since the snail travelled due north, the speed is therefore 8.3×10¯⁴ m/s North.
8. Determination of speed of the runner.
The following data were obtained from the question:
Distance travalled = 8 m
Time = 4 secs
Speed =?
Speed = Distance travalled / time
Speed = 8/4
Speed = 2 m/s
Therefore, the speed of the runner is 2 m/s.
A jogger runs 224 meters eastward, then 156 meters
westward, then 84 meters eastward, and finally 248 meters westward.
What is the distance, magnitude and the direction of the displacement?
Explanation:
Distance is the length of the path traveled. Displacement is the difference between the final position and initial position.
Distance = 224 m + 156 m + 84 m + 248 m = 712 m
Displacement = 224 m − 156 m + 84 m − 248 m = -96 m
Displacement = 96 m westward
Given the following equation, solve for r.
Answer:
r = √(GMm/F)
Explanation:
F = GMm/r²
We can make r the subject of the above equation as follow:
F = GMm/r²
Cross multiply:
F × r² = GMm
Divide both side by F
r² = GMm/F
Take the square root of both side
r = √(GMm/F)
Thus, r is √(GMm/F)
Define principal focus of concave mirror.Where should we place a candle in front of a concave mirror to get an enlarged,erect image?
Explanation:
The principal focus of a concave mirror is defined as the point when the ray of light that are parallel to the principal axis converge.It is denoted by letter F.When the object is placed between the focus and the pole of the concave mirror, the image is formed behind the mirror.The formed image is enlarged in size than the object.A virtual and erect image is formed.The attached figure shows the whole scenario.we do not get hurt while jumping of aeroplane with a parachute,Why?
Answer:
this is because of air resistance
Explanation:
air resistance is a type of friction in air. It acts on the parachute as an upward force and slows the person speed while falling.
A polar bear runs at a speed of 11 m/s and has a mass of 380.2 kg. How much Kinetic energy does the bear have?
Answer:
[tex] \boxed{\sf Kinetic \ energy \ of \ the \ bear (KE) = 23002.1 \ J} [/tex]
Given:
Mass of the polar bear (m) = 6.8 kg
Speed of the polar bear (v) = 5.0 m/s
To Find:
Kinetic energy of the polar bear (KE)
Explanation:
Formula:
[tex] \boxed{ \bold{\sf KE = \frac{1}{2} m {v}^{2} }}[/tex]
Substituting values of m & v in the equation:
[tex] \sf \implies KE = \frac{1}{2} \times 380.2 \times {11}^{2} [/tex]
[tex] \sf \implies KE = \frac{1}{ \cancel{2}} \times \cancel{2} \times 190.1 \times 121 [/tex]
[tex] \sf \implies KE = 190.1 \times 121 [/tex]
[tex] \sf \implies KE = 23002.1 \: J[/tex]
[tex] \therefore [/tex]
Kinetic energy of the polar bear (KE) = 23002.1 J
In 1869 Dmitri Mendeleev was trying to arrange the 65 known elements in a logical way. He arrived at the solution when he saw the elements arranged by atomic weight in a dream . He tried this arrangement and it worked. What is this an example of?
Answer: Creative thinking
Explanation:
It should be noted that, Creative Thinking is the method by which a problem is solved with the help of thinking skills.
The thought that is present in mind is tries in the practical life so that the problem can be solved.
Going by the question asked, Mandleev was trying to arrange elements in a logical way. He thought of arranging the elements based on the atomic weight.
This gives a good oexample of creative thinking in which the thinking is applied and a logical result is product of the thinking.
Answer:
Creative thinking
Explanation:
An athlete runs some distance before taking a long jump. Why ?
An athlete runs before taking a long jump because they need to gather the strength to jump its like a person brain storming before they write an essay
a 1.2 x 10^4 kg railroad car is coasting along a level, frictionless track at a constant speed of 25m/s, when a 3000 kg load is dropped vertically onto the car from above. What will its new speed be assuming the load stays on the car??
Answer:
[tex]20\; \rm m \cdot s^{-1}[/tex].
Explanation:
Because the track is level and frictionless, the net force on this car-load system will be zero in the horizontal direction. As a result, (by Newton's Second Law of mechanics,) the total momentum of this system in the horizontal direction will stay the same.
Momentum of the car-load system in the horizontal direction, before contact:
Car: [tex]m(\text{car}) \cdot v(\text{car, before}) = 1.2 \times 10^{4}\; \rm kg \times 25\; m \cdot s^{-1} = 3.0 \times 10^{6}\; \rm kg \cdot m \cdot s^{-1}[/tex].Load: zero (for it is dropped "vertically.")Combine the two parts to obtain: [tex]p(\text{system, before}) = 3.0 \times 10^{6}\; \rm kg \cdot m \cdot s^{-1}[/tex].
Because the load stays on the car, the car and the load should have the same horizontal velocity after contact. Let [tex]v(\text{system})[/tex] denote that velocity. Momentum of the system after contact:
Car: [tex]m(\text{car}) \cdot v(\text{car, after}) = 1.2 \times 10^{4}\; \rm kg \times (\mathnormal{v}(\text{system}))[/tex].Load: [tex]m(\text{load}) \cdot v(\text{load, after}) = 3000\; \rm kg \times (\mathnormal{v}(\text{system}))[/tex].Combine to obtain:
[tex]p(\text{system, after}) =1.5\times 10^{4}\; \rm kg \times (\mathnormal{v}(\text{system}))[/tex].
Because the total momentum of the system will stay the same:
[tex]\begin{aligned}&1.5\times 10^{4}\; \rm kg \times (\mathnormal{v}(\text{system}))\\ &= p(\text{system, after}) \\&= p(\text{system, before}) \\ &= 3.0\times 10^{6}\; \rm kg \cdot m \cdot s^{-1}\end{aligned}[/tex].
Solve for [tex]v(\text{system})[/tex] to obtain:
[tex]v(\text{system}) = 20\; \rm m\cdot s^{-1}[/tex].
In other words, the new velocity of the system would be [tex]20\; \rm m \cdot s^{-1}[/tex].
A hockey puck moves 28 m southward then 14 m northward and finally 4 m southward Distance? And Magnitude and Direction
Explanation:
Given that,
A hockey puck moves 28 m southward then 14 m northward and finally 4 m southward distance.
The total path covered is called distance and the shortest path covered is called displacement.
Distance = 28 m + 14 m + 4 m
Distance = 46 m
Let the nothward direction is positive y axis and southward direction is negative y axis.
Displacement is equal to the difference of final position and the initial position.
Displacement =-28 m - (-4 m)
= -24 m
The magnitude of displacement is in south direction.
Two resistors connected in series (R1, R2) are connected to two resistors that are connected in parallel (R3,R4). The series-parallel combination is connected to a battery. Each resistor has a resistance of 10.00 Ohms. The wires connecting the resistors and battery have negligible resistance. A current of 2.00 A runs through resistor R1. What is the voltage supplied by the voltage source?
Answer:
50volts
Explanation:
Each of the resistance is 10ohms. 2 in series and 2 in parallel. it means the 2 parallel can combines with total of 10×10÷(10+10)= 5ohms and combine in series with 10ohms which is 10+10+5= 25ohms. in series connection, we have same current flowing. therefore the voltage source will be 25ohms × 2amps = 50volts
what is the force constant of a spring
which is stretched 4m by a force of 200N
Explanation:
Hooke's law:
F = kx
200 N = k (4 m)
k = 50 N/m
someone that would help me! <33
Answer:
Option A is correct.
Explanation:
In the given triangle , x is the base and 14 is the hypotenuse for angle 33°.
cos 33 = base / hypotenuse
Putting the given values
cos 33 = x / 14
.84 = x / 14
x = .84 x 14
= 11.7
Option A is correct.
What is the velocity of an object that has a momentum of 4000 kg-m/s and a mass of 115 kg? Round to the nearest hundredth.
A. 36.5 m/s
B. 37.43 m/s
C. 34.78 m/s
D. 35.67 m/s
Answer:
C. 34.78 m/s
Explanation: hope this helps ;)
Before stating the problem, research is often required.
True
False
Answer:
The correct answer is certainly true.
Explanation:
You first need to fully understand the conflict/problem before explaining it.
Most students do this when doing a research project.
For example: Let's say I had a project to explain solutions for climate change but I didn't even know what it is and how it was caused. Well of course your teacher will make you research the topic in order to represent it correctly.
can an object under constant acceleration come to rest and stay at rest?
Explanation:
No. If the object stays at rest, its acceleration is 0. So the acceleration must have changed.
Read the scenario below and identify the Independent Variable, Dependent Variable, the Control group, and at least two Constants. Suggest a hypothesis for each scenario: After studying about recycling in his new issue of Organic Compost Quarterly, members of Filbert's compost club decided to investigate the effect of various recycled products on plant growth. Filbert's friends finally decided to compare the effect of different aged grass compost on Jalapeno pepper plants. Because decomposition is necessary for release of nutrients, the group hypothesized that older grass compost would produce taller pepper plants. Three flats of pepper plants (25 plants/flat) were grown for 5 days. The plants were then fertilized as follows: Flat A: 450 g of three-month-old compost Flat B: 450 g of six-month-old compost Flat C: 0 g of compost The plants received the same amount of sunlight and water each day. At the end of 30 days the group recorded the height of the plants (cm) and then threw a party featuring Jalapeno peppers stuffed with cream cheese!
Answer:
The independent variable: is the amount of compost applied to each plant
The dependent variable: the height of the plants
Hypothesis: Older grass compost will produce taller plants
Three groups were created:
the control group is group C to which no compost was applied
investigated group A and B with different amounts of compost applied
Explanation:
The students are considering using the scientific method to analyze the problem.
The independent variable is the one controlled by the researcher and the dependent variable is the response of the system
The independent variable: is the amount of compost applied to each plant
The dependent variable: the height of the plants
Hypothesis: Older grass compost will produce taller plants
Three groups were created:
the control group is group C to which no compost was applied
investigated group A and B with different amounts of compost applied
If the length of a pendulum is doubled,what will be the change in its time period??
Explanation:
see the attachment.. hope it will help you
Please help ASAP! Thank you :)
The earth's orbit is oval in shape. Explain how the magnitude of the gravitational force between the earth and the sun changes as the earth moves
from position 'A' to 'B' as shown in the figure.
Answer:
The Sun's gravitational force is like the tetherball rope, in that it constantly pulls Earth toward it. Earth, however, like the tetherball, is traveling forward at a high rate of speed, which balances the gravitational effect. ... Instead, it travels in a nearly circular motion around the Sun, creating an orbit.
Answer:
Explanation:
Yep
17. A force of 150N is applied at an angle of 60°
to the horizontal to pull a box through a
distance of 50m. Caleulate the work done.
B. 3750J C.6495J
E. 8660J
A. 1500J
R 7500J
Answer:7,500J
Explanation:
Work done=force× distance
Please Answer ASAP :)
The weight of a body of certain mass becomes zero in space. Why? Write with reason
Because theres no gravity, so it means that gravity = 0.
using the weight formula
weight = mass × gravity
= mass × 0
= 0N
An average family of four uses roughly 1200 liters of water per day (1L = 1000 Com). A lake that covers 50 km with a uniform depth and
supplies water to a local town with a population of 40,000 people would lose
depth every year due to water consumption form
the locals. Ignore evaporation, rain, creeks and rivers
Answer:
A family of 4 uses 1200 liters of water per day
1200 liters/day * 365 days/year = 438000 liters per year
If the town has 40,000 people, this equals 10,000 families
Explanation:
So the total town usage in one year = 10000*438000 = 4.38E9 liters = 4.38E12 cm^3 (scientific notation)
The area of the lake in cm^2 is 50 km^2 * (100 cm / m)^2 * (1000 m / km)^2 = 5E11 cm^2
The loss of volume of the lake is 5E11 cm^2 * h, where h is the change in depth
The total volume of water used by the town = the volume lost by the lake.
Therefore 4.38E12/5E11 = h = 8.76 cm
please help ASAP thanks
Answer:
Precipitation
Explanation:
Ocean water may evaporate and precipitate into the river.
b
Alpha Centauri has an apparent magnitude of -0.27, whereas the apparent
magnitude of Alpha Crucis is 0.77. Identify which star appears brighter when observed from
Earth. Explain your answer.
Answer:
Alpha centauri will be brighter than Alpha Crucis .
Explanation:
Apparent magnitude of a star measures how bright a star is .
This scale is reverse logarithmic ie , the brighter the star , the lower is its magnitude . A magnitude equal to 5 scale higher represents less magnitude by a factor of 1/ 100 . In this way a difference of 1 magnitude represents a brightness ratio of 2.512 . Hence a star of brightness magnitude of 7 is less bright by a factor 2.512 than that of a star magnitude of 6 .
A finch rides on the back of a Galapagos tortoise, which walks at the stately pace of 0.060 m/s. After 72 seconds the finch tires of the tortoise’s slow pace, and takes flight in the same direction for another 72 seconds at 12 m/s. What was the average speed of the finch for this 144-second interval?
Answer:
The average speed of the finch is: 6.03 m/s
Explanation:
Recall that the average value of a function in a given interval is defined as the integral of the function (area under the curve the function describes) in that interval, divided by the length of the interval.
In this case, the function that describes the speed of the finch (in the vertical axis) as a function of time (in the horizontal axis), is a piecewise function that consists of two horizontal lines (one at y = 0.06 between 0 and 72 seconds in the horizontal axis, and the other one at y = 12 between 72 and 144 in the horizontal axis).
The area of such function is simply the addition of the areas of two rectangles, both of the same width (72 seconds) but of different heights (one 0.06 m/s and the other one 12 m/s)
Then these areas add up to give:
0.06 * 72 + 12 * 72 = 868.32 m
When we divide this by the length of the interval of integration (144 seconds) to calculate the average speed, we get:
average speed = 868.32/144 = 6.03 m/s
Please help anyone knows the answer?!!!
Answer:
b) east
Explanation:
centripetal force f= ma
An aircraft has a liftoff speed of 33 m/s. What minimum constant acceleration does this require if the aircraft is to be airborne after a take-off run of 240 m
Answer:
2.27 m/s²
Explanation:
Recall that one of the equations of motion can be expressed as
v² = u² + 2as
where
v = final velocity = takeoff speed = 33m/s
u = initial velocity = rest = 0 m/s
a = acceleration ( we are asked to find this)
s = distance traveled = length of takeoff run = 240m
substituting the known values into the equation above,
v² = u² + 2as
33² = 0² + 2a(240)
1089= 480a
a = 1089/480
a = 2.27 m/s²
ANSWER
2.27 m/s^2
EXPLANATION
We can use the general relationship from kinematics:
vf^2 = vi^2 + 2as
where:
s = distance;
a = acceleration;
vi = 0m/s is the initial velocity;
vf=33ms is the final velocity.
So:
33^2 = 0^2 + 2 ⋅ a ⋅ 240
a= 1089/480
= 2.27m/s^2
An object is attached to a vertical spring and bobs up and down between points A and B. Where is the object located when its kinetic energy is a maximum?
a. At either A or B
b. Midway between A and B
c. One third between A and B
d. One-fourth of the way between A and B
Answer: Midway between A and B
a. Midway between A and B
What is Kinetic Energy?The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
A mass spring system will trace a sinusoidal curve as a function of time, similar to any object vibrating in simple harmonic motion.
a. In a two and fro motion, the velocity of the mass is greatest at the center, thus the kinetic energy is maximum at the equilibrium position.
b. At the equilibrium position, the total energy of the system is in the form kinetic energy and the potential energy is zero.
Therefore there no force exerted on the mass. Since there is no force and the velocity of the mass is maximum , acceleration of the mass is zero.
c. The total energy in the mass spring system is comprised of potential energy and kinetic energy. Since the energy is conserved in nature, the kinetic energy at the equilibrium position is maximum and therefore the potential energy should be zero at the equilibrium position.
Therefore,
Kinetic energy is maximum Midway between A and B.
Learn more about Kinetic energy here:
https://brainly.com/question/12669551
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Una ola en el océano tiene una longitud de 15m. Una onda pasa por una determinada positionfija cada 3s. ¿Cuál es la velocidad de la onda?
Answer:
La velocidad de la onda es 5 m/s.
Explanation:
La velocidad de la onda puede calcularse como:
[tex] v = \frac{\lambda}{T} [/tex] (1)
Donde:
λ: es la longitud de onda de la ola = 15 m
T: es el período = 3 s
Entonces, reemplazando los valores de T y de λ en la ecuación (1) tenemos:
[tex] v = \frac{\lambda}{T} = \frac{15 m}{3 s} = 5 m/s [/tex]
Por lo tanto, la velocidad de la onda es 5 m/s.
Espero que te sea de utilidad!