Answer:
A
Explanation:
PLS HEP WILL GIVE BRAINLIEST TO FIRST ANSWER SCIENCEE!!
Answer:
Claim: The heart pumps more blood throughout the body when one exercises because exercise takes a lot of energy from the body.
Evidence: Heart rate went from 80 bpm to 120 bpm
Reasoning: Doing exercise takes a lot of energy to do, causing the circulatory system to have to work harder and pump more blood throughout the body in order to allow someone to be able to do a task that involves so much movement and energy.
Explanation:
Waves are often caused by
a
vibrating objects.
b
colliding objects.
c
potential energy.
d
mechanical energy.
Answer:
vibrating objects.
I think
Waves are often caused by vibrating objects. Based on the type of vibrational motion, there are different types of waves. Hence, option a is correct.
What are waves ?Waves are disturbances in air or the passage of energy through vacuum or through a medium. Waves are caused by vibration of objects. Three are two types of waves broadly, mechanical waves and electromagnetic waves.
Electromagnetic waves are those associated with combined electric and magnetic field. They can pass through both vacuum and mediums. Mechanical waves need a medium to pass and does not transfer through vacuum.
Based on the vibrational motion, there are two types of waves longitudinal waves and transverse waves. In transverse waves, the vibrational motion of particles is perpendicular to the wave propagation.
In the case of transverse waves, the particle vibration is along the wave propagation. Hence, option A is correct.
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Why is a teacher's feedback valuable?
Answer:
Because they could help you move on better with your strategy and ultimately get you better scores on tests
Answer:
Through feedback, teachers can provide the students with suggestions for development, learning strategies and corrections for errors. The importance of constructive feedback allows for many positive opportunities. This component also enhances a student's self-efficacy and provides an avenue for motivation.
Why must the rockets use great force to get into outer space?
1. A student notices that wearing darker colors in sunlight makes him feel warmer, so he decides to conduct an experiment. He takes five pieces of different-colored cloth and wraps
each one around a water bottle. He then places all five bottles in direct sunlight and measures the temperature of the water in each bottle an hour later.
What should be kept constant throughout this experiment?
O the color of the cloth
O the temperature of the water
the amount of water in each bottle
O the temperature of the outside air
Answer: the color of the cloth
Explanation:
Which statement is true?
Every magnesium (Mg) atom has atomic number of 12.
Every magnesium (Mg) atom has a mass number of 24.
this is science but i just put physics
Answer:
Every magnesium (Mg) atom has atomic number of 12.
Explanation:
Magnesium (Mg) is a chemical element of great importance for plants, animals, and humans.
Alkaline earth metal, magnesium is obtained by electrolysis of magnesium chloride solution.
Magnesium burns with a shining flame. Magnesium is a good reducing agent. This property is used to obtain some other metals.
9. A student notices that wearing darker colors in sunlight makes him feel warmer, so he decides to conduct an experiment. He takes five pieces of different
colored cloth and wraps
each one around a water bottle. He then places all five bottles in direct sunlight and measures the temperature of the water in each bottle an hour later
What is the dependent variable in this experiment?
O the time he leaves it in the sunlight
O the amount of water in each bottle
O the color of the cloth
O the temperature of the water
Answer: 4
Explanation:
The dependent variable is the temperature of the water.
Directions: Summarize the main ideas of this lesson by answering the question below.
How might a person acquire a fear of or aversion to something even though it has no negative effect
on him or her?
Answer:
Explanation:
Trypophobia is a fear or disgust of closely-packed holes. People who have it feel queasy when looking at surfaces that have small holes gathered close together.A person may start by imagining what they fear, then looking at pictures of the fear object, and then finally being near or even touching the source of their anxiety. In the case of trypophobia, a person with symptoms may start by simply closing his eyes and imagining something such as a honeycomb or seed poThey can help you find the root of the fear and manage your symptoms. Last medically reviewed on July 20, 2017 Medically reviewed by Timothy J. Legg, Ph.D., CRNP — Written by Annamarya Scaccia ...
Alex wants to learn how to surf, but he is not a strong swimmer. He knows he needs to increase his ability to paddle out in order to catch the best waves. Which piece of advice would you give to help him get started on reaching his goal? He should swim at least three times a week at the community pool to build stamina. He should tread water every day to get more comfortable in the water. He should purchase the best surfboard he can afford because it will help him paddle faster. He should watch your friend who is a competitive surfer practice to learn her technique.
Answer:
He should swim at least three times a week at the community pool to build stamina.
Explanation:
the ocean contains many plants and protists that can make their own food through photosynthesis. Which need do these organisms get by living near the surface that they cannot get in deep water?
shelter
oxygen
sunlight
Answer:
sunlight
Explanation:
Photosynthesis is made possible by energy from the sun.
---Spring Question---
A 0.84 kg ball is held at rest against a spring (k = 142 N/m) that has been compressed 0.06 m. The ball and spring are on a table and the ball is 2.0 m above the ground. If friction between the ball and the table is negligible, then how far from the edge of the table (in meters) will the ball hit the ground?
Answer:
The distance from the edge of the table at which the ball will hit the ground is approximately 0.49 meters
Explanation:
The mass of the ball = 0.84 kg
The spring constant k = 142 N/m
The compression of the spring = 0.06
Therefore, by conservation of energy, we have;
The potential energy of the spring = The kinetic energy given to the ball
The potential energy of the spring = 1/2 × k × x² = 1/2 × 142 × 0.06² = 0.2556
The potential energy of the spring = 0.2556 J
The kinetic energy given to the ball = 1/2 × m × v²
Where;
v = The final velocity of the ball
Substituting gives;
1/2 × 0.84 × v² = 0.2556
∴ v = √(0.2556/(1/2 × 0.84)) ≈ 0.78
The final velocity of the ball = v ≈ 0.78 m/s
The height of the ball above the ground, h = 2.0 m
Therefore, we have;
The time, t, it takes the ball to touch the ground from the 2.0 m height, h, is given as follows;
h = 1/2·g·t²
t = √(2·h/g)
Where;
g = The acceleration due to gravity = 9.81 m/s²
∴ By substitution, we have;
t = √(2 × 2/9.81) ≈ 0.63855
t ≈ 0.63855 s
The distance from the edge of the table at which the ball will hit the ground = The horizontal distance covered during before the ball hits the ground
The horizontal distance covered during before the ball hits the ground = The (horizontal) velocity of the ball × The time it takes the ball to touch the ground
∴ The horizontal distance covered during before the ball hits the ground = 0.78 × 0.62855 ≈ 0.490269 ≈ 0.49
The distance from the edge of the table at which the ball will hit the ground = The horizontal distance covered during before the ball hits the ground ≈ 0.49 m
A race car makes one lap around a track with a radius of 41 meters in 8 seconds. What is the velocity?
Answer:
31.21 m/s
Explanation:
radius=41m
time = 8 sec
circumference=2πr
from formula
circumference=2×22/7×41
=257.71m
now
velocity=total distance( circumference)/total time
=257.71/8
= 32.21m/s
The velocity of race car makes one lap around a track with a radius of 41 meters in 8 seconds is 32.19 m/s
What is velocity ?Velocity is "rate of change of displacement with respect to time".
i.e. v= dx/dt
it is also defined as displacement over time. i.e. v=Displacement/Time.
Velocity shows how much distance can be covered in unit time. It's SI unit is m/s. It is vector quantity ( having both direction as well as momentum). where displacement is distance from mean position.
Given,
Radius of the track r= 41m
time taken by car to complete one lap T = 8s
velocity v = ?
we know that ω = 2π÷T
ω = 2×3.14 ÷ 8
ω = 0.785 rad/s
v=rω
v= 41×0.785
v= 32.185 ≅32.19 m/s
Hence velocity of the car is 32.19 m/s
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A crate is being pulled down an incline as shown in the figure. With respect to the crate's direction of motion, which of the following forces does only negative work on the crate?
Answer:Fn
Explanation:
If u drop a bar of soap on the floor then is the floor clean or is the bar of soap dirty? Lol I’m so bored i dont even know what I’m doing.
Answer:
CLEAN
Explanation:
Answer:
I just wash mine with water when I drop it . That is a good question tho :)
Explanation:
What is thermodynamics?
a) the way energy changes
b) the classification of energy
c) the movement of energy
d) the movement of heat
Answer:
I think it is D
Explanation:
Answer:
D :D lol
Explanation:
A 10 kg object experiences an acceleration of 2 m/s squared. What net force was applied to the object?
F = ma
= 10kg × 2m/s
= 20N
Answer : 20N
Explanation :
F = Force (N)
m = mass (kg)
a = acceleration (m/s)
While delivering 125 kg blocks of ice to a local village, Kristoff and his family (and Sven too) come upon a cliff that is 5.7 m above them. To solve their problem, they build a catapult that will launch their blocks of ice with an initial velocity of 15 m/s and at an angle of 45 degrees above the ground.
Prove that the catapult will successfully launch the ice blocks up to the top of the cliff. Quantities you will need to solve for will be initial vertical velocity, horizontal velocity, the distance the catapult is from the cliff, and the amount of time it takes the ice to reach the cliff. Assume that they are experts and have arranged everything so that the ice blocks just barely reach the top of their parabolic path when they land at the top of the cliff and make a smooth landing. Draw a picture of the scene to help you visualize what is happening.
After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
What is the rate of acceleration while the blocks slow to a stop?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
Answer:
a. Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
b. -2.81 m/s²
c. 3.78 s
d. -351.25 N
Explanation:
a. After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
For the block of ice to reach the top of the cliff, its maximum height, h should be greater than or equal to 5.7 m. That is, h ≥ 5.7 m.
The maximum height of a projection h, projected with an initial velocity v at an angle Ф is h = v²sin²Ф/2g where g = acceleration due to gravity = 9.8 m/s².
For the block of ice, v = 15 m/s and Ф = 45°. So,
h = v²sin²Ф/2g
= (15 m/s)²sin²45/(2 × 9.8 m/s²)
= 225 (m/s)²(1/√2)²/19.6 m/s²
= 225 (m/s)²(1/2)/19.6 m/s²
= 112.5 (m/s)²/19.6 m/s²
= 5.74 m
Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
The graph is in the attachment.
b. What is the rate of acceleration while the blocks slow to a stop?
Using v² = u² + 2as where u = initial horizontal velocity of block = 15m/scos45° = 10.61 m/s, v = final velocity of block = 0 m/s since it stops, a = acceleration and s = distance block moves = 20 m
So, a = (v² - u²)/2s
substituting the variables into the equation, we have
a = ((0 m/s)² - (10.61 m/s)²)/2(20 m)
= - 112.57 (m/s)²)/40 m
= -2.81 m/s²
c. How long do the blocks take to slow to a stop?
Using v = u + at where u = initial horizontal velocity of block = 10.61 m/s v = final velocity of block = 0 m/s since it stops, a = acceleration = -2.81 m/s² and t = time it takes block of ice to stop
So, making t subject of the formula,
t = (v - u)/a
substituting the values of the variables, we have
t = ( 0 m/s - 10.61 m/s)/-2.81 m/s²
= -10.61 m/s/-2.81 m/s²
= 3.78 s
d. What is the amount of friction between the ice and the snowy ground?
The frictional force, f = net force on block of ice
f = ma where m = mass of bock = 125 kg and a = acceleration of block = -2.81 m/s²
f = ma
= 125 kg(2.81 m/s²)
= -351.25 N
As you travel downhill, your vehicle needs less power to reach the bottom and your stopping _________ increases.
Answer: Distance
Explanation:
When driving, it is important for one to always use safety belt and obey traffic rules.
During a collision, it is vital to always adhere to safety belts and also use occupant protection systems in order to help reduce the impact that an be felt during a collision. As you travel downhill, your vehicle needs less power to reach the bottom and your stopping distance increase.
A single celled organism is found in a sample of water. It contains a nucleus as well as other membrane bound organelles and possesses collagen for movement. This organism most likely belongs to which kingdom?
Answer:
Explanation:
The cell is the smallest living organism that contains all the features of life, and most all life on the planet begins as a single-cell organism. Two types of single-celled organisms currently exist: prokaryotes and eukaryotes, those without a separately defined nucleus and those with a nucleus protected by a celluA single-celled organism is found living in a deep sea vent at the bottom of the ocean in extremely hot water. If it is examined further, which of the following is most likely to be found within it? It will have DNA that is not contained in a nucleus since it is likely a member of the domain Archaea.lar membrane.
URGENT! 40 POINTS! For each situation below, find the work done on the box using both energy and forces.
1. A 2 kg box initially at rest slides down a frictionless ramp (at 15ᵒ from the ground) for
1 second.
2. A 2 kg box is thrown upward with an initial speed of 3.5 m/s. Consider the box from
the time it was thrown until it reaches its maximum height.
3. A 2 kg box is dropped from an initial height of 10 m.
I have some physics, I just don't know what formulas to use or where to start. Help is much appreciated.
Answer:
i’m not sure one second let me try to figure it out
Explanation:
A car drives 500m in 2 minutes.What is the cars speed? A.2m/s B.4m/s C.5 m/s
Answer:
B
Explanation:
1 minute = 60 seconds
2 minutes = 2 * 60 = 120 seconds.
d = r * t
t = 120 seconds
d = 500 meters
r = d/t
r = 500 / 120 = 4.167 m/s
The closest answer is B
what is not a raquet sport
Answer:
what
Explanation:
Racket sports include tennis, badminton, squash or any other sport where you use rackets to hit a ball or shuttlecock to play. They can be played competitively or just for fun and are a great form of physical activity.
Joe and Jim start at rest at the starting line of a race track. Both runners accelerate at the same rate, but Joe accelerates for twice as long as Jim. Describe the final speed of Joe compared to Jim.
Answer:
Vf₂ = 2 Vf₁
It shows that final speed of Joe is twice the final speed of Jim.
Explanation:
First, we analyze the final speed of Jim by using first equation of motion:
Vf₁ = Vi + at
where,
Vf₁ = final speed of Jim
Vi = initial speed of Jim = 0 m/s
a = acceleration of Jim
t = time of acceleration for Jim
Therefore,
Vf₁ = at ---------------- equation (1)
Now, we see the final speed of Joe. For Joe the parameters will become:
Vf = Vf₂
Vi = 0 m/s
a = a
t = 2t
Therefore,
Vf₂ = 2at
using equation (1):
Vf₂ = 2 Vf₁
It shows that final speed of Joe is twice the final speed of Jim.
A sign is attached to the side of a building as seen below. The sign is attached to a steel rod. A wire connects to the end of the rod for support. The mass of the sign is 50 kg. Determine the supporting force exerted by the cable
Answer:
500N
Explanation:
50kgx10N/kg
= 500N
The magnitude of vector vector A is 84.9 m and it points in the +y axis direction. The magnitude of vector vector B is 195.0 m and it points at an angle of 41.0° counterclockwise from +x axis. The magnitude of vector vector C is 126.2 m and it points in the +x axis direction.
Solution:
The magnitude of A vector is 84.9 m in the positive y-axis direction.
So the X component of A =0
the Y component of A = 84.9 m
Now the magnitude of B vector is 195 m and it makes an angle of 41° in the direction from the positive x-axis direction.
So the X component of B = B cos 41°
= 195 x cos 41°
= 195 x 0.75 = 146.25 m
the Y component of B = B sin 41°
= 195 x sin 41°
= 195 x 0.65 = 126.75 m
Now it is given that vector C has a magnitude of 126.2 m and it makes a direction towards the positive x-axis.
So the X component of C =126.2 m
the Y component of C = 0
Comparing all these, we get
1. B vector has the largest X component
2. B vector has the largest Y component
According to Kepler's second law of planetary motion,
O a. planets maintain constant speed around the Sun.
Ob. the area swept out by the orbit per time unit keeps changing.
O c. the speed of a planet is greatest when it is closest to the Sun.
O d. planets maintain constant acceleration around the Sun.
Answer:
c. the speed of a planet is greatest when it is closest to the Sun.
Explanation:
Johannes Kepler was an astronomer who discovered that planets had elliptical orbits in the early 1600s (between 1609 and 1619).
The three (3) laws published by Kepler include;
I. The first law of planetary motion by Kepler states that, all the planets move in elliptical orbits around the Sun at a focus.
II. According to Kepler's second law of planetary motion, the speed of a planet is greatest when it is closest to the Sun.
Thus, the nearer (closer) a planet is to the Sun, the stronger would be the gravitational pull of the sun on the planet and consequently, the faster is the speed of the planet in terms motion.
III. The square of any planetary body's orbital period (P) is directly proportional to the cube of its orbit's semi-major axis.
Answer:
A planet moves faster when it is closer to the Sun.
Explanation:
Kepler law!
In a place covered by shadow of cloud sun cannot be seen . Explain with reasons .
Answer:
Because even though our eyes have a huge dynamic range (ability to pick out details in sharply lit and lesser lit areas simultaneously) than any camera, there's a limit.
When there's strong sunlight, your pupils contract and let less light in, which makes the shadows look darker.
When it's cloudy, your pupils widen and let more light in, which makes the shadows look less dark.
Do some experiments with a camera and you'll soon get the hang of it.
NOTE: Also test HDR (high dynamic range) photography, where the camera takes three or more pictures in quick succession, with different exposure settings, and combines them to get the most detail of both bright and dark areas. The result is more or less what we percieve.
Work is a _______ acting upon an object for a given ______. The amount of work done is equal to the change in ________ of the object.
Answer:
Work is a FORCE acting upon an object for a give DISTANCE. The amount of work done is equal to the change in KINETIC ENERGY of the object.
Explanation:
The answer is from the definition and equations for work:
Work = force*distance = change in kinetic energy
Answer:
energy
Explanation:
i took the quiz
Four measurements of the file card's width are made. Of the measurements given below, the LEAST precise.
O 7.62
O 7.63
O 7.34
O 7.6
help me with this please :((
Answer:
huh?
Explanation: