Answer:
The Doppler Effect is given by the following relation;
[tex]f' = \left (\dfrac{v + v_0}{v - v_s} \right) \times f[/tex]
Where;
f' = The frequency the observer hears
f = Actual frequency of the wave
v = The velocity of the sound wave
[tex]v_o[/tex] = The velocity of the observer
[tex]v_s[/tex] = The velocity of the source
Where the observer is stationary, we have;
(i) When the source is moving in the direction of the observer
[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]
(ii) When the source is receding from the observer, we have;
[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]
Therefore;
(a) A person left behind on the platform
For a person left behind on the platform, we have that the radio source is receding, therefore, we have;
[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]
(1) Given that (v + [tex]v_s[/tex]) > v, therefore, v < (v + [tex]v_s[/tex]), f' < f, the frequency heard by the person left on the platform, f', is smaller (lower) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively smaller
(b) A person down below floating on a rubber raft
For the the person down below on the rubber raft, the radio source is advancing
Therefore, the radio source is moving towards the person at rest down on the rubber raft, therefore, we have;
[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]
(1) Given that (v - [tex]v_s[/tex]) < v, therefore, f' > f, the frequency heard by the person down below floating on the rubber raft, f', is greater (higher) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively greater (higher)
Explanation:
4. Given that the specific heat of copper is 385J/kg/K and if 81.2J of heat is applied to 17.8g of copper by how much will the temperature of the copper increase?
Answer:
11.85 k
Explanation:
11.85 k
Which of the following is the best
definition of tissue?
1 Pt
A
B
A. what organs are made of
B. your skin and muscles
C. parts of cells
D. a group of similar cells working together
E. None of the above
What is atomic composition
Answer:
The atom consists of a tiny nucleus surrounded by moving electrons. The nucleus contains protons, which have a positive charge equal in magnitude to the electron's negative charge. The nucleus may also contain neutrons, which have virtually the same mass but no charge.
Explanation:
Assume you have a person with a mass of 65 kg riding a skateboard down a ramp. While they are
still 4.8 m high, they are traveling at a speed of 8.0 m/s.
a) Calculate the Eg. [write here)
b) Calculate theEk [write here]
c) Calculate the Etotal. [write here]
d) If the ramp had a total height of 8.0 m, what would be their Eg, Ek, and Etotal at that height?
Answer:
a) Eg = 3,060.72 j
b) Ek = 2,080 j
c) Etotal = 5,140.72 j
d) Eg = 5,140.2 j
Ek = 0 j
Etotal = 5,140.2 j
Explanation:
The given parameters of the person riding the skateboard are;
The mass of the person, m = 65 kg
The height of the person (above ground level), h = 4.8 m
The speed at which the person is traveling, v = 8.0 m/s
a) The gravitational potential energy, Eg = m·g·h
Where;
m = The mass of the object at the given height = 65 kg
g = The acceleration due to gravity, g ≈ 9.81 m/s²
h = The height by which the object is elevated = 4.8 m
∴ Eg = 65 kg × 9.81 m/s² × 4.8 m = 3,060.72 joules
The gravitational potential energy, Eg = 3,060.72 J
b) The kinetic energy, Ek, is given as follows;
Ek = 1/2·m·v²
Where;
v = The velocity of the object = 8.0 m/s
∴ Ek = 1/2 × 65 kg × (8.0 m/s)² = 2,080 joules
The kinetic energy, Ek = 2,080 J
c) The total mechanical energy, Etotal = Eg + Ek
∴ Etotal = 3,060.72 j + 2,080 j = 5,140.72 J
The kinetic energy, Ek = 5,140.72 J
d) If the ramp had a total height of 8.0 m, we have;
At the 8.0 m height
Etotal = Eg(max), Ek = 0 j
With the given values, we get;
Eg(max) = 65 kg × 9.81 m/s² × 8 m = 5,101.2 joules = Etotal
Eg(max) = 5,101.2 j
Etotal = 5,101.2 j
Ek = 0 j
However, using only the values in the question with the assumption that all things being equal, we have;
Etotal = Constant = 5,140.72 j
Eg a the max height, 8.0 m = Eg(max) = Etotal = 5,140.2 j
Ek = 0 j
what is the difference between storm spotter and storm chaser?
Answer:
this is just a guess
Explanation:
a storm spotter only spots the storm and a storm chaser looks for the storm????
11. A sensitive thermometer is one which
A. Is sensitive to heat
B. has large bore
C. can record big changes in temperature
D. can record small changes in temperature
Answer:
A. ls sensitive to heat
this is correct answer
I hope it's helpful for you.......
a car travels for two hours at an average speed of 36 km/h how far will the car travel
Answer:
259200
Explanation:
use the formula distance= speed x time
change the 2 hours to seconds (7200) and multiply that number by 36 and it'll give you 259200
Answer:
12 kilometers and hour
Explanation:
At an amusement park, a swimmer uses a water slide to enter the main pool If the swimmer start at rest slides without friction and descend through a vertical height of 2.31m what is her speed at the bottom of the slide
Answer:
v = 6.72 m/s
Explanation:
Given that,
Vertical height, h = 2.31 m
We need to find the speed at the bottom of the slide. Let the speed be v. We can find it using the conservation of energy such that,
[tex]\dfrac{1}{2}mv^2=mgh\\\\v=\sqrt{2gh}[/tex]
Put all the values,
[tex]v=\sqrt{2\times 9.8\times 2.31} \\\\v=6.72\ m/s[/tex]
So, her speed at the bottom of the slide is equal to 6.72 m/s.
NO LINKS OR UNUSEFUL ANSWERS
What is the trade off between the input and output forces when someone uses a screw?
The weight of a cuboid box is 288 N. Find its mass.
Answer:
29.39 kg
Explanation:
From the question,
W = mg...................... Equation 1
Where W = weight of the cuboid box, m = mass of the cuboid box, g = acceleration due to gravity.
make m the subject of the equation
m = W/g.................. Equation 2
Given: W = 288 N
Constant: g = 9.8 m/s²
Substitute these values into equation 2
m = 288/9.8
m = 29.39 kg
the impact of unemployment in South Africa
Answer: Unemployment has both individual and social consequences that require public policy interventions.
For the individual, unemployment can cause phycology distress which can lead to a decline in life satisfaction it can also lead to mood disorders and substance abuse
Describe how Newton's 1st Law of Motion is used on a daily basis at school.
Can you please answer my question correctly ASAP
Answer:
1) C, 2) C, 3) B, 4) D, 5) A/B, 6) D, 7) D, 8) A, 9) B, 10) A
Explanation:
1) Seconds, minutes and days are time units. (Correct answer: C)
2) The displacement is shortest distance between the point of origin and the point of destination. (Correct answer: C)
3) The velocity is the rate of change of position in time. (Correct answer: B)
4) Graphs are a very useful ressource to infer characteristics inherent to a studied physical variable. (Correct answer: D)
5) There are two possible answers, since both milimeters and meters are units for distance. (Correct answers: A/B)
6) The distance is the arc length of the entire path that object travelled. (Answer: D)
7) Traditionally, in a position vs. time graph we plot time in the x-axis. (Answer: D)
8) In this case, we use a distance-time graph, where travelled distance is the dependent variable and time is the independent variable. (Answer: A)
9) The point of origin is the initial position of the object. (Answer: B)
10) The point of destination is the final position of the object. (Answer: A)
I lift a 20kg ball up 2.5 meters off the ground on Earth.
-Earth’s gravitational acceleration is about 9.8 m/s2.
How much gravitational potential energy does the ball have at this point? _____________
How much work did I do lifting up the ball? _____________________________________
If I lift the same ball the same distance on the Moon, then how much gravitational potential energy will it have? (Moon’s Gravity = 1.6 m/s2) ____________________________________
Answer: How much gravitational potential energy does the ball have at this point? At h = 20.4 m the gravitational potential energy of the ball reaches maximum.
How much work did I do lifting up the ball? As you are lifting the object you are doing work on the object. The work W done on an object by a constant force is defined as W = F·d. It is equal to the magnitude of the force, multiplied by the distance the object moves in the direction of the force.
You want to create a model that conducts electricity. Which material should you use?
A. Glass
B. Plastic
C. Wood
D. Copper
Answer:
D. Copper
Explanation:
Copper has the best electrical conductivity of any metal, except silver. A good electrical conductivity is the same as a small electrical resistance.
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The velocity of a car increases from +4.0 m/s to +16.0 m/s
in a time period of 4.0 s. What was the average
acceleration?
Answer:
Explanation:
Although we do have an equation for this in terms of one-dimensional motion, it's easy enough just to use the mathematical definition of acceleration:
[tex]a=\frac{v_f-v_0}{t}[/tex] which says, in words, the acceleration of an object is equal to the objects final velocity minus its initial velocity, divided by the change in time. Since everything is given in m and s, our answer will be in m/s/s:
[tex]a=\frac{16.0-4.0}{4.0}[/tex] and
[tex]a=\frac{12.0}{4.0}[/tex] so
a = 3.0 m/s/s
How did Shi Huangdi link the new lands of his empire
Answer:
Many things, such as building the Great Wall of China, and building highways.
Explanation:
Which is one use of lasers
A. reproducing images to make them clearer
B. Producing a magnified image of the moon
C. Cutting an iron bar into two pieces
D. Making a leaf appear larger so it’s veins are visible
Answer:
c
Explanation:
because what else can the laser be used for
what is conservation of energy in physics?
Answer:
https://www.khanacademy.org/science/physics/work-and-energy/work-and-energy-tutorial/a/what-is-conservation-of-energy
Explanation:
Look at this website it gives you all the details! :)
Which action MOST LIKELY occurred in order for the sugar to dissolve?
Answer:
In order for sugar to dissolve, there must be an attraction between the two substances.
Explanation:
Water and sugar are both attracted to each other, which is why sugar is able to dissolve in water.
Hope this helps! :)
Answer:
the water was stirred
Explanation:
it’s need as a type of attraction
A 1400 kg car traveling at 17.0 m/s to the south collides with a 4700 kg truck that is at rest. The car and truck stick together and move together after collision. What is the final velocity of the two-vehicle mass? If Kinetic Energy = 0.5 * m * v^2, calculate the KE before the crash and the KE of the combined vehicles after the crash.
Answer:
Final velocity = 7.677 m/s
KE before crash = 202300 J
KE after crash = 182,702.62 J
Explanation:
We are given;
m1 = 1400 kg
m2 = 4700 kg
u1 = 17 m/s
u2 = 0 m/s
Using formula for inelastic collision, we have;
m1•u1 + m2•u2 = (m1 + m2)v
Where v is final velocity after collision.
Plugging in the relevant values;
(1400 × 17) + (4700 × 0) = (1400 + 1700)v
23800 = 3100v
v = 23800/3100
v = 7.677 m/s
Kinetic energy before crash = ½ × 1400 × 17² = 202300 J
Kinetic energy after crash = ½(1400 + 1700) × 7.677² = 182,702.62 J
Electromagnetic radiation travels as
1.
a torsional wave
2.
a longitudinal wave
3.
a transverse wave
4.
an elliptical wave
A 1.3 kg book has 11.7 joules of potential energy relative to the floor when it's sitting on top of
Brenda's dresser. Calculate how tall Brenda's dresser is?
GIVING BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 25pts-
Answer:
c
Explanation:
heat is thermal energy transferred from a hotter system while temperature is a measure of the average kinetic energy of atoms or molecules in the system
A spiral staircase winds up to the top of a tower in an old castle. To measure the height of the tower, a rope is attached to the top of the tower and hung down the center of the staircase. However, nothing is available with which to measure the length of the rope. Therefore, at the bottom of the rope a small object is attached so as to form a simple pendulum that just clears the floor. The period of the pendulum is measured to be 8.5 s. What is the height of the tower
Answer:
L = 17.94 m
Explanation:
The angular velocity of a simple pendulum is
w = [tex]\sqrt{ \frac{g}{L} }[/tex]
the angular velocity is related to the period
w = 2π / T
we substitute
[tex]\frac{4\pi ^2 }{T^2} = \frac{g}{L}[/tex]
L = [tex]\frac{g T^2}{4 \pi ^2}[/tex]
let's calculate
L = 9.8 8.5² / 4π²
L = 17.94 m
The tallest Ferris wheel in the world is located in Singapore. Standing 42 stories high and holding as many as 780 passengers, the Ferris wheel has a diameter of 150m and takes approximately 30 minutes to make a full circle. Determine the speed of the riders (in m/s) on the Singapore Flyer.
Answer:
The speed of the riders on the Singapore Flyer is approximately 0.262 m/s
Explanation:
The dimensions of the tallest Ferris wheel in the world are;
The diameter of the Ferris wheel, D = 150 m
The tine it takes the Ferris wheel to make a full circle, T = 30 minutes = 30 min × 60 s/min = 1,800 seconds
The angular velocity of the Ferris wheel, ω = 2·π/T
The linear velocity of the Ferris wheel, v = r·ω = The speed of the riders
Where;
r = The radius of the Ferris wheel = D/2
D = 150 m
∴ r = 150 m/2 = 75 m
∴ v = r·2·π/T
∴ v = 75 m × 2 × π/(1,800 s) ≈ 0.262 m/s
The speed of the riders on the Singapore Flyer, v ≈ 0.262 m/s
imagine no girls awnser this question ://
Answer:
im confused
Explanation:
Water is a great conductor of electricity. True or False
Answer:
False
Explanation:
Think about every warning on electrical products, which is 'DO NOT KEEP NEAR WATER'
Answer:
FALSE
Explanation:
Pure water is not a good conductor of electricity. ... Because electrical current is carried by ions in solution, conductivity increases as the ion concentration increases. In such a way, that the conductivity when water dissolves ionic compounds.
Forces at a Distance
Use Equation: e-r/T
If the distance between the two foci in an orbit is 4 AU, and the length of the major axis is 9 AU, what is the eccentricity of the orbit?
O 0.888
O 0.222
O 2.25
O 0.444
How much force is needed to keep the bowling ball moving towards the pins once it has
left the man's hand?
PLEASE HELP!
Answer:
a lot of force is the answer
Explanation:
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