Answer:
I believe B. The picture is not completely clear
Explanation:
A box is pushed using 500 joules of energy. The amount of energy produced is
50 J. Calculate the efficiency.
2. An athlete runs up the stairs of a tall building in 10 s. If she has a mass of 55 KG and the total vertical distance she covers is 8.2 m, what is the average power (in W)developed by her legs?
Answer:
P = 37.0 W (watts)
Explanation:
Using the formula for power :
P = ( kg × m^2/s^2 ) W
given the mass 55kg, the time 10s, and the displacement 8.2m.
55 kg × 8.2^2 / 10^2
55kg × 67.24 / 100
3698.2/100
P = 36.982 ≈ 37.0 W (nearest tenth)
Explain which planets have seasons and why some planets have none at all.
Discuss which planet has seasons most similar to earth and why.
Discuss additional factors that some planets have that affect their seasons.
What fact about other planet’s seasons most surprised you and what did you find the most interesting? Why?
Answer:
Some planets have seasons some don't bc of the distance from the sun some of them are too cold or too hot to have seasons
An underwater sound source emits waves of frequency 30 kHz in all directions. How does the intensity of the waves (in Watts/m2) vary with distance r from the source?
a) 1/r^3
b) 1/r^2
c) 1/r
d) None of above
When an underwater sound source emits waves of frequency 30 kHz in all directions, the intensity of the waves (in Watts/m2) vary with distance r from the source by the relation 1/r²
As the intensity mechanical sound wave is inversely proportional to the square of the distance from the source, therefore the correct option is B.
What is the Wavelength?Wavelength can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The intensity of a mechanical wave is inversely proportional to the square of the distance from the source.
An underwater sound source emits waves of frequency of 30 kHz in all directions, the intensity of the waves (in Watts/m2) varies with distance r from the source by the relation 1/r², therefore the correct option is B.
Learn more about wavelength from here
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A person has a mass of 1000 g and an acceleration of 20 M/S/S what is the force on the person
Answer:
The answer is 20 NExplanation:
The force acting on an object can be found by using the formula
force = mass × accelerationFrom the question
mass = 1000 g = 1 kg
acceleration = 20 m/s²
We have
force = 20 × 1
We have the final answer as
20 NHope this helps you
a car get slips in a mud
Answer:
So, if the car slips in mud it will either skid or slide depending on the size of the mud puddle.
Does this work?
2.9030 has 4 significant digits.
TRUE OR FALSE
all the elements are found on earth, where were they formed?
1. in the sun
2. in ancient stars
3. in earths core
4. in the gas cloud that formed earth
Answer:
in the Earths core
Explanation:
PLEASE PLEASE HELP PICTURE INCLUDED
Answer:
an electro magnet is technology contain at least one permanent magnet
Using complete sentences and correct punctuation and grammar answer the following question. Must be at least 3 sentences.
Explain why Eclipses do not occur every month.
Answer: A solar eclipse occurs when the moon passes in between the Earth and sun, casting a shadow down on the surface of our planet. If you're in the path of the shadow, the moon destroys the sun. No, wait, I mean the moon blocks the sun briefly.A lunar eclipse happens when the moon passes through the Earth's shadow. We see one limb of the moon darken until the entire thing is in shadow.An eclipse does not occur every month, because one month after an eclipse the relative geometry of the Sun, Moon, and Earth has changed. As seen from the Earth, the time it takes for the Moon to return to a node, the draconic month, is less than the time it takes for the Moon to return to the same ecliptic longitude as the Sun.
Explanation:
Answer:
Because the moon's orbit wobbles up and down with respect to the Earth, the satellite's shadow can be too high or too low to cause a solar eclipse. If the moon partially covers the sun for a given location, that area experiences a partial solar eclipse. But if the moon fully covers the sun, it will cause either a total solar eclipse or an annular solar eclipse; that's when a bright ring of light is still visible in the sky around the dark silhouette of the moon.
According to the kinetic theory, what happens when the temperature of water
increases?
The water molecules increase their speed.
The water molecules do not change speed.
The water molecules decrease their speed
PLEASE HELP
In the periodic table, the number of valence electrons in each element decreases from left to right across each period.
Select one:
O True
O False
can you pls give a question about science. like why does the sky blue? PLS HELPPP ASAP
A microwave oven operates at 2.00 GHz . What is the wavelength of the radiation produced by this appliance?
Answer:
Wavelength = 0.15 m
Explanation:
The frequency of a microwave oven is 2.00 GHz or [tex]2\times 10^9\ Hz[/tex].
We need to find the wavelength of the radiation produced by this appliance. We know that the relationship between the frequency and wavelength is given by :
[tex]c=f\lambda[/tex]
Where,
[tex]\lambda[/tex] is the wavelength
So,
[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{2\times 10^9}\\\\=0.15\ m[/tex]
So, the wavelength of the radiation produced by this appliance is 0.15 m.
A force vector has a magnitude of 42 N and is applied at an angle of 108°
above the eastern horizontal.. Determine they component of this force
vector
0 -15 N
O -13 N
39.9 N
35 N
A car start from rest accelerate uniformly at rate of 2 m/sec2. Its velocity after 5 seconds will be:
Answer:
nononononononononononononnn
Explanation:
Answer:
Read below to understand
Explanation:
acceleration = change in velocity / change in time
(a = v/t)
You have acceleration and time given so you need to rearrange the equation to solve for velocity
V = a * t
V = 2 * 5
Velocity is 10 m/s
A shot-putter exerts an unbalanced force of 128 N on a shot giving it an acceleration of 19
m/s2. What is the mass of the shot?
Answer:
128 is the ans cuz N is also lnown as mass
Explanation:
128
water vapor is what kind of gas?
Answer:
the gaseous phase of water
Explanation:
"It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. "
hope this helps!!
Water vapor is a greenhouse gas.
I know this is a simple answer, but I sincerely hope this helped!
As part of their research on cell reproduction, Ms. Kelly's biology class designed various experiments to determine the best conditions for budding, or asexual reproduction, in common yeast cells. The students added sucrose as a source of food for the yeast and each group added water of a different temperature to the yeast-sugar mix. They used a light microscope to observe and count the yeast cells.
Based on the recorded data, what observation did the students make regarding the growth of yeast cells?
A) Once the temperature reached 50oC, the yeast died.
B) The size of individual yeast cells increased with an increase in temperature.
C) Increased temperature played no role in increasing the number of yeast cells.
D) The number of yeast cells increased as the temperature of the water increased.
A rock climber is going up a narrow space between two vertical rocks. The distance between the rocks allows the climber to brace herself using friction, where her feet are flat and in contact with one rock to the left, and her legs are straight horizontal and her back is flat against a rock on the right. The coefficient of static friction between her shoes and the rock on the left is 1.2, and between the rock at right and her back is 0.8. The climber relaxes until she is on the verge of slipping on both sides.
(a) Draw a FBD for the climber
(b) What fraction of her weight is supported by the frictional force on her shoes?
Answer: b
Explanation:
The jogger ran 3km east.
4. Look at the bottom figure. Suppose that a car is 20 km due north of New York City. The car
travels north toward Albany until it is 100 km due north of New York City.
Answer: d
Explanation:
A car accelerates from rest to a certain velocity in a certain time. Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)
Answer:
it will take half of the initial time to reach double the velocity
Explanation:
Given that a car accelerates from rest to a certain velocity in a certain time.
Since the car accelerate from rest, the initial velocity U = 0
Using the first equation of motion,
V = U + at
V = at
Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)
That is V = 2V
Using the same formula ,
2( at ) = at
2T = t
T = t/2
Therefore, it will take half of the initial time to reach double the velocity
When light waves hit ice, most of them bounce off and radiate back into space. Because of this, ice is best described as which kind of surface?
Answer:
Reflective surface
Explanation:
Ice is a reflective surface because most the of the light waves that hits on it bounces off.
When a surface is smooth and polish, it acts a reflector. When a surface is jagged and not smooth light does not readily reflect. Reflection is through the incident angle of the light waves.Therefore, snow is a reflective surface.
The vehicle land-speed record has long been held by rocket cars. These vehicles resemble the high-speed rocket planes that were used in the early days of the space program, but they have heavy metal wheels. On September 5, 1997, the world land-speed record was set by the British-built Thrust SSC rocket car, which had a top recorded speed of 341 m/s. The kinetic energy of the car at this speed is 5.289 × 108 J. What is the car’s mass?
Answer:
9096.93 Kg
Explanation:
The following data were obtained from the question:
Velocity (v) = 341 m/s
Kinetic energy (KE) = 5.289×10⁸J.
Mass (m) =.?
The mass of the car can be obtained as follow:
KE = ½mv²
5.289×10⁸ = ½ × m × 341²
5.289×10⁸ = ½ × m × 116281
5.289×10⁸ = m × 58140.5
Divide both side by 58140.5
m = 5.289×10⁸ / 58140.5
m = 9096.93 Kg
Therefore, the mass of the car is 9096.93 Kg
Are Stereotyping and prejudice are the same thing true or false
Answer:
Yes it's false for this finish touch
It takes 25.7 N to push a crate
at a constant speed across flat
ground where uk
= 0.238.
What is the normal force acting
on the crate?
(Unit = N)
Answer:
108 N
Explanation:
Divide the force by uk to get the normal force
(25.7)/(0.238) = 107.98 N = 108 N
Answer:
107
Explanation:
My question is on the picture
Answer:
Measure change in temperature after long call
Explanation:
Glucose is a carbohydrate.
True
0r False
Answer: True
Explanation: Glucose is a carbohydrate.
Atoms tend to be stable and nonreactive if they have six valence electrons.
Select one:
O True
O False
Answer:
True
Explanation:
A rubber cord catapult has cross-sectional area
25mmand initial length of rubber cord is 10c.
Its is stretched to 5cm and then released to
project a missile of mass 5gm. Taking
Yubber = 5x108N/m² velocity of projected
missile is :
(1) 20ms -
(2) 100ms
(3) 250ms
(4) 200ms)