Answer:
a. Vf = 39.24 [m/s]
b. Vf = 31.24 [m/s]
c. Vf = 47.24 [m/s].
Explanation:
To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.
[tex]v_{f}=v_{o}+g*t[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (when the rock is dropped)
g = gravitational acceleration = 9.81 [m/s²]
t = time = 4 [s]
a.
[tex]v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s][/tex]
b.
In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.
[tex]v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s][/tex]
The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.
c.
[tex]v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s][/tex]
Which of the following is true about sound waves?
1:they move faster than light
2:they make wind
3:the vibrate the air
4: they move slower in water than air
Answer:
They transmit by vibration through mediums such as air. So #3 is most logical answer.
Explanation:
It is in fact vibration of air (sound waves) which is transformed by the tympanic membrane in the ear of human to audible sounds.
++++++++++++++++++++++++++++++++++++++++++++++
Sound travels slower than light
Move faster in water than air.
Wind blowing through leaves and other objects creates sounds.
Answer:
(Question) Which type of wave needs a medium to travel?
(Answer) sound waves, because they travel by oscillating molecules
(Question) What do both sound and light waves transfer?
(Answer) energy
(Question) How does an increase in amplitude affect sound and light waves?
(Answer) louder sound and brighter light
(Question) What happens to the wavelength when the frequency increases?
(Answer) The wavelength decreases.
(Question) Which of the following is true about sound waves?
(Answer) Sound moves faster in the ocean than in the air.
Explanation:
i just did the quick check
HELP ASAP!!!!!!! PLEASE WILL GIVE BRAINLIEST
Name the three major parts of a cell and their functions
Answer:
Cell Membrane (Plasma Membrane)
Cytoplasm.
Nucleus.
Explanation:
The cytoplasm is home to many activities of the cell as it contains molecules, enzymes that are crucial in the break down of the waste. The cytoplasm also assists in metabolic activities. Cytoplasm provides shape to the cell. It fills up the cells thus enabling the organelles to remain in their position.
The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell. And that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.
The nucleus controls and regulates the activities of the cell (e.g., growth and metabolism) and carries the genes, structures that contain the hereditary information. Nucleoli are small bodies often seen within the nucleus.
Fossils are rare because certain conditions are needed to preserve an organism in order for it to fossilize, and those conditions themselves are rare. Which of these conditions is LEAST likely to result in fossilization? A) Organism has an exoskeleton. B) Organism lives in or near water. C) Organism lives in a colder climate. D) Organism is prey to several species.
Answer:
D
Explanation:
The least of the conditions that can result in fossilization would be when an organism is a prey to several species.
Fossils are remains or traces of organisms that have been geological preserved and a prey is an organism that is often hunted and serves as food to bigger organisms. When an organism is eaten, the probability of it becoming a fossil becomes low. Unless such an organism is usually partially eaten by predators, there would not be any remains, let alone being fossilized.
The correct option is D.
A car starting from rest accelerated at the rate of 0.5 m/s². What would be the final velociety of the car and how much time would it take to cover 1.6kms?
Answer:
1) 800m/s
2) 2 seconds
Explanation:
Acceleration= velocity/time
Where acceleration= 0.5 m/s²
Time= 1.6kms= 1.6×10^3 seconds
If we substitute we have
0.5=v/(1.6×10^3)
V=800m/s
the final velociety of the car is 800m/s
Velocity= distance/time
800= (1.6×10^3)/ time
Time= 1.6×10^3/800
=2 seconds
Hence the time it will take to cover is 2seconds
Suggest a form of renewable energy that could be used to power an electric ticket machine that only needs to work during daylight hours.
Answer:
solar panel or wind turbine
Explanation:
Because solar panel gives energy to electricity by sun and wind turbine gives energy through wind and both are renewable
Renewable energy that could be used to power an electric ticket machine that only needs to work during daylight hours is solar energy.
What is solar energy?Solar energy is the term for solar radiation that can create heat, trigger chemical reactions, or create electricity. The total solar energy incident on Earth is far greater than the global energy needs at the moment and in the future. This highly distributed source has the ability to meet all future energy demands if properly exploited.
Due to its limitless supply and lack of pollution, solar energy is predicted to become a more appealing renewable energy source in the twenty-first century than the finite fossil fuels coal, petroleum, and natural gas.
Although sunlight is by far the most potent energy source that Earth receives from the Sun, its intensity at the surface of the planet is actually rather modest.
This is primarily due to the massive radial radiation propagating from the far-off Sun. Earth's atmosphere and clouds, which absorb or scatter as much as 54% of the incoming sunlight, cause a comparatively small additional loss.
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A pendulum on earth oscillates with a period of 3.45 seconds. What is the length of the pendulum?
Answer:
The length of the pendulum is 2.954 m.
Explanation:
Given;
period of the pendulum, T = 3.45 s
The period of the pendulum oscillation is given as;
[tex]T = 2\pi \sqrt{\frac{l}{g} } \\\\\frac{T}{2\pi} = \sqrt{\frac{l}{g} }\\\\\frac{T^2}{4\pi ^2} = \frac{l}{g} \\\\l = \frac{gT^2}{4\pi ^2} \\\\[/tex]
where;
L is length of the pendulum
g is acceleration due to gravity on Earth = 9.8 m/s²
[tex]l = \frac{gT^2}{4\pi ^2}\\\\l = \frac{(9.8)(3.45)^2}{4\pi ^2}\\\\l = 2.954 \ m[/tex]
Therefore, the length of the pendulum is 2.954 m.
When the notebook is sitting on the table, what force prevents it from falling into the space below the table? If you don’t know the name of this force, just describe it. What force keeps the notebook from floating in the air?
Answer:
reaction force/normal force (its when the tables kinda pushing from under so it doesnt fall)
and the notebook wont float bc of gravity
Explanation:
theres a quizlet on this if you wanna check it out lol
Answer:
The table surface pushes the notebook from below and prevents it from falling. (This force is called the normal force.) Gravity, or a pull from Earth, keeps the notebook from floating in the air.
Explanation:
Which characteristic of a sound is affected by the amount of energy used to create that sound? In what direction the sound will travel how fast or slow the sound travels in a particular medium how high or low the sound's pitch is how loud or soft the sound is
Answer:
The correct option is;
How loud or soft the sound is
Explanation:
The loudness of a sound wave is given by the amount of energy that the pressure wave carries and it is measured in decibels (dB) which is the relative intensity of the pressure wave of a sound to the standard pressure
A loud sound has a high amplitude and a soft sound has a low amplitude, such that as the amplitude of the sound is increased, due to increased energy input, the sound becomes louder, and as the amplitude of the sound is decreased due to reduced energy input, the sound becomes softer.
Which type of fault is shown by the illustration below where the hanging wall moves down relative to the foot wall?
A. normal fault
B. reverse fault
C. strike slip fault
D. thrust fault
Answer:
A. normal fault NOT
B. reverse fault YES IT IS
Explanation:
I hope this helps
Have a Blessed Day
What is the distance between a 2000 kg truck and a 3000 kg truck if the gravitational force between them is 0.00006 N?
A 258
B. 567 m
C 981
D. 15
Answer:
A. 2.58m
Explanation:
Using the formula;
F = GMm/r²
M and m are the masses
G is the gravitational constant
r is the distance between the masses
Substitute
0.00006 = 6.67*10^-11(2000)(3000)/r²
0.00006r² = 6.67*10^-11*6000000
0.00006r² = 40.02*10^-5
0.00006r² = 0.0004
r² = 0.0004/0.00006
r² = 6.66
r = 2.58m
Hence the distance between them is 2.58m
11. A ball is thrown up and attains maximum height of 20 m. Calculate its initial speed. (g = 10 ms')
a) 19.7 m/s
b) 20 m/s
c) 25 m/s
d) 35m/s
final velocity = 0
acceleration = - 10 m/ s 2
distance. = 20 m
u = ?
v^2 - u ^2 = 2 a s
0^2 - u^ 2 = 2 * -10 * 20
-u^2 = -400
u = √ 400
u = 20m / s
A rope hangs between two cliffs, edge A and edge B. There is a 250 kg hiker sliding across and is closer to
edge A than edge B. The angles that the ropes make below the horizontal are 35° below edge A and 65° below
edge B. What is the Tension in both ropes?
Answer:
1655.5 N
Explanation:
We resolve the forces on the rope into horizontal and vertical components. Since the only vertical force exerted on the rope is the weight of the man, this weight equals the vertical components of the tensions on both sides of the rope .
The only horizontal forces acting on the rope are horizontal components of both tensions on both sides. Since the hiker doesn't move sideways, they cancel out and he is balanced. So, the net horizontal force is zero.
Let T be the tension in the rope. So, each vertical component on side A is Tsin35° and that on side B is Tsin65°. Let the weight of the man be W = mg where m = mass of hiker = 250 kg and g = acceleration due to gravity = 9.8 m/s².
So, since the hiker balances, Tsin35° + Tsin65° = mg
0.5736T + 0.9063T = 250 kg × 9.8 m/s²
1.4799T = 2450 N
dividing both sides by 1.4799, we have
T = 2450 N/1.4799
T = 1655.52 N
T ≅ 1655.5 N
So, the tension in the rope equals T = 1655.5 N
The boy a projects a ball downwards with velocity v ,where it reaches the boy b after 0.5 s . So the ball the reaches the ground after time ...... from the moment of projection (g=10 m/s2)
Answer:
the answer i
Explanation:
A student decides to make some extra money during a snow day. As the neighborhood kids are outside sledding, the student offers to pull the students to the top of the hill for one dollar per ride. The sled-puller noticed that it was taking more time to pull older children to the top than with the younger children even though they were pulling with the same force.
Explain why some kids took longer to pull to the top of the hill then other kids despite pulling with the same force. Be sure to address the following for 2 points each:
Identify the formula used to calculate the force of each pull up the hill.
Identify what was different about the older children compared to the younger children that affected the trips up the hill
Explain how this demonstrates Newton's Second Law of Motion
Answer: 5.5 mass
Explanation: The force of gravity pulling the car up the hill = 5.5
23. If a jogger runs 100 meters west and then turns around and runs 30 meters east. What
was the jogger's displacement?
a. 70 meters.
b. 130 meters.
C. 30 meters.
d. 100 meters.
Answer:
A
Explanation:
if he goes to the west, the east is opposite so 100-30
The jogger's displacement was 70 meters. Hence, option (a) is correct answer.
What is displacement?The term "displacement" refers to a shift in an object's position. The symbol for it is an arrow pointing from the initial location to the ending place.
Displacement is a vector quantity as both magnitude and direction are required for defining displacement. SI unit of Displacement is meter.
Given parameter:
The first displacement of the jogger is = 100 meters along west direction.
The second displacement of the jogger is = 30 meters along east direction.
Hence, resultant displacement of the jogger along west direction = 100 meters - 30 meters
= 70 meters.
Hence, the magnitude of jogger's displacement was 70 meters. Hence, option (a) is correct answer.
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where would you expect light waves to move faster?
a - in space
b- through an iceberg
c- under the sea
d- on a mountain top
Answer:
a
Explanation:
work done by a gravitational force by lowering the bucket into the well is
Answer:
when we lower a bucket into a well to fetch water, the work done by gravity is positive since force and displacement are in the same direction.
Explanation:
What is the MAIN idea of the section "Green Loses Its Power In Fall"?
If you are holding a stack of books at your waist and then you walk across the room your hands did?
1) efficiency
2) power
3) work
4) no work
Answer:
3. Work
Explanation:
Number 1 isn't correct because you are not using efficiency to hold books and walk across the room.
Number 2 could be correct but isn't in this situation because you use power only to hold the books but not to walk across the room.
Number 4 is not correct because you need to do work to do something.
What is the kinetic energy of a 2000 kg car that is traveling 10 m/s
Answer:
100,000 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 2000 \times {10}^{2} \\ = 1000 \times 100 \\ = 100000[/tex]
We have the final answer as
100,000 JHope this helps you
an object has a weight on the surface of the earth of 370 N. What is the mass
Explanation:
The mass of the object is 370N / (9.81N/kg) = 37.7kg.
who is the best soccer player?
PLEASR HELP ME, WILL GIVE BRAINLIEST
a sportsman rushed the circle 15 times in 1/6 hour. distance of this running track 0.4 km. what is the average speed of sportsman?
a) 20 m/s
b) 50 m/s
c) 35 m/s
d) 10 m/s
e) 25 m/s
f) 20.5 m/s
(an answer with explanation would be great)
Answer:
d. 10 m/s
Explanation:
2. Explain how the number of batteries and the number of coils of wire affect the strength of an electromagnet.
Answer:
The more the number of batteries and coils, the more the electromagnetism.
Explanation:
An electromagnet is a structure formed by passing electricity through a good conductor. Due to the 'Magnetic Effect Of Electric Current', the object functions as an electromagnet, that is, by attracting magnetic objects to it.
This intensity of electromagnetism is greatly dependent on the Electric flow or Current as well as the Number of coils on the electromagnet.
By increasing the number of coils in the electromagnet, you actually increase the electric flow per area or the Magnetic Induction, helping to broaden its magnetic field.
The more batteries you connect to a circuit, the more will be its voltage. Similarly, the more batteries you connect to an electromagnet, the greater will be its strength, due an increased flow of electrons.
A solar-powered car has a kinetic energy of 110250 J. Its mass is 180 kg. Work out how fast the car is travelling.
Answer:
35 m/s
hope this helpedd
Explanation:
Kinetic Energy 1 upon 2 into mass into velocity square
1 upon 2 into 180 into velocity square=110250
v^2=110250 multiple by 2 and divided by 180
And take square root
which property makes radio waves ideal for carrying and transmitting data?
a.) having long wavelengths
b.) having high frequencies
c.) transferring high amounts of energy
d.) traveling faster than the speed of light
Answer:
a.) having long wavelengths
Explanation:
Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m. Therefore, radio waves are a series of repetitive valleys and peaks that are typically characterized of having the longest wavelength in the electromagnetic spectrum.
Basically, as a result of radio waves having long wavelengths, they are mainly used in long-distance communications such as the carriage and transmission of data. Some examples of communication technologies that uses radio waves are radio set, mobile phones, television etc.
Hence, the property which makes radio waves ideal for carrying and transmitting data is that, it is having long wavelengths.
Answer:
A. having long wavelengths
Explanation:
How high must you lift a 25 Newton book for it to have the same increase in potential energy as a 20 Newton book that was lifted to 0.5 meters?
Given :
An object with weight 20 N was lifted to 0.5 meters.
To Find :
How high must you lift a 25 Newton book for it to have the same increase in potential energy as the given book.
Solution :
Since both have same potential energy :
[tex]P.E_2 = P.E_1\\\\W_2h_2 = W_1h_1[/tex]
Putting all given values in above equation :
[tex]25h_2 = 20\times 0.5\\\\h_2 = \dfrac{20\times 0.5}{25}\\\\h_2 = 0.4\ m[/tex]
Therefore, book with same potential energy is at a height of 0.4 m.
A balloon tied up with a wooden piece is moving upward with velocity of 15m/s. At a height of 300m above the ground, the wooden block detached from the balloon. How much time will it take to reach the ground?
question is attached!
Answer:
For Bill to dump the water on Tim, Tim should be 7.232 meters from the tree when Bill dumps the water
Explanation:
The given height above the ground at which Bill sits on the tree branch with a bucket of water, h = 4.0 meters
The speed with which Tim is approaching the tree = 8.0 meters per second
The time , t, it will take for the bucket of water to reach the ground is given by the equation of free fall as follows;
h = 1/2·g·t²
Where;
h = Height = 4.0 m
g = The acceleration due to gravity ≈ 9.8 m/s²
t = The time
Making t the subject of the above equation gives;
t = √(h/(1/2·g))
Substituting the known values gives;
t = √(4.0 m/(1/2 × 9.8 m/s²)) ≈ 0.904 s
t ≈ 0.904 seconds
Therefore, for Bill to dump the water on Tim, it should take Tim approximately 0.904 seconds to get to the tree
The distance, d, Tim will be when it will take him 0.904 seconds to get to the tree is given from the kinematic equation of speed, s, as follows;
Distance, d = Time, t × Speed, s
Where;
d = The distance
t = The time = 0.904 s
s = The speed with which Tim is approaching the tree = 8.0 m/s
Substituting the values gives;
d = 0.904 s × 8.0 m/s = 7.232 m
Therefore, the distance Tim should be when Bill throws the water = 7.232 meters
A car was moving a 14 m/s. After 30 seconds, it’s speed increased to 20 m/s. What was its acceleration during this time?
Answer:
acceleration = 0.2 m/s/s
Explanation:
initial velocity u = 14
final velocity v = 20
time = 30
acceleration = ?
v = u + at
20 = 14 + 30a
30a = 6
a = 0.2 m/s/s
Answer:
For the aceleration we have:
V = Vi + a * t
Being:
V = 20 m/s
Vi = 14 m/s
a = ?
t = 30 s
Then, lets replace acording the formula:
20 m/s = 14 m/s + a * 30 s
Clear "a":
a = (20 m/s - 14 m/s) / 30 s
a = (6 m/s) / 30 s
a = 0,2 m/s²
The aceleration of the car is 0,2 meters per second squared.