3. A person of mass 100 kg stands on a scale in an elevator. The elevator moves downward at a steady speed. Is the scale reading greater than, less than, or equal to 1000 N? Justify your answer.
Answer:
less than
Explanation:
Given;
mass of the person, m = 100 kg
acceleration due to gravity, g = 9.8 m/s²
The reading on the scale is determined by applying Newton's second law of motion;
R = mg - ma
R = m(g-a)
at constant velocity, the acceleration is zero
a = 0
R = m(g-0)
R = mg
R = 100 x 9.8
R = 980 N
Thus, the scale reading is equal to the weight of the person but less than 1000 N
a mineral has a mas of 53grams. Its volume is 12millileters. What is the
density?
Answer:
636
Explanation:
Answer:
4.45 g/mL
Explanation:
to get density, you simply divide the volume by the mass, so your equation would look like p= 53/12
P being density, which is what you are solving for! Hope this helps!!
a car travels at a speed of 30 mph. how far does the car travel in 2 hours
Answer:
The car would travel 60 miles in 2 hours.
Explanation:
The distance for an hour is already given, 30 miles per hour.
Given this you could multiply 30 by 2 which gives you 60.
The distance of the car is its speed times the time taken. The speed of the car is 30 miles per hour and time of travel is 2 hours. Then, the distance travelled is 60 miles.
What is speed?Speed of a moving object is the measure of the distance travelled per unit time. The rate of speed is called velocity. Velocity of an object is a vector quantity.
As the object is covering more distance within small time, then the object is said to have greater speed. Speed of an object also depends on is mass.
Given the speed = 30 mph
time taken = 2 hours
distance = speed × time
= 30 × 2 = 60 miles.
Therefore, the distance travelled by the car is 60 miles.
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What is the displacement of the elevator between 8 s and 24 s?
Answer:
The displacement of the elevator between 8 s and 24 s is 6 m.
Explanation:
Given that,
Initial time = 8 s
Final time = 24 s
We know that,
Displacement :
Displacement is the difference between initial position and final position.
In mathematically,
[tex]D=x_{f}-x_{i}[/tex]
We need to calculate the displacement
Using formula of displacement
[tex]D=x_{f}-x_{i}[/tex]
Put the value from graph
[tex]D=15-9[/tex]
[tex]D=6\ m[/tex]
Hence, The displacement of the elevator between 8 s and 24 s is 6 m.
Answer:
See attached.
Explanation:
See attached.
Un cuerpo de m=0,5 Kg se desplaza horizontalmente con v=4m/s y luego de un lapso de tiempo se mueve con v=20 m/s. ¿cual ha sido la variación de la energÍa cinética?
Responder:
64 JuliosExplicación:
La energía cinética se expresa mediante la fórmula KE = 1 / 2mv² donde;
m es la masa del cuerpo
v es la velocidad del objeto
Dado que el cuerpo se mueve horizontalmente con v = 4 m / sy después de un período de tiempo se mueve con v = 20 m / s, entonces la variación en la velocidad será de 20 m / s - 4 m / s = 16 m / s.
Parámetros dados
masa del objeto m = 0,5 kg
Variación de velocidad = 16 m / s
Variación de la energía cinética = 1/2 * 0,5 * 16²
Variación de la energía cinética = 1/2 * 0,5 * 256
Variación de la energía cinética = 0,5 * 128
Variación de la energía cinética = 64 Julios
Sea and land breezes over a large region that change direction with the seasons are called_____________.
X-rays are used to take pictures of your bones. UV rays just burn your skin. Why do you think x-rays can go through skin and UV rays cannot?
(Please help, And try to be as detailed as possible.)
Answer:
yes x rays are like light rays the difference is that they v
can oass through stuffs
skin and fats doesn't block more of the x rays
Explanation:
why uv cannot go through it us dangerous causing skin disease and cancer,skin itchness and redness and ut is cumulative
state the sources of alternating current
Answer:
hudroelectricity
..........
Answer:
generator, crystal oscillator, alternator are sources of AC current.
What is energy????????
Answer:
Energy is the ability to do work.
Explanation: Work is just the act of displaying something by applying force.
what are the three parts to tell the cell theory
Answer: 1. Organisms are made of cells
2. Cells are the most fundamental unit of life
3. Cells come from other cells
Explanation:
Hope this helps!!
The United States spends over $20 billion a year on space exploration through NASA. Do you think that this has been worth the cost? In three to five sentences, provide two specific examples of things we have learned from space exploration, and explain how these examples influence your opinion.(4 points)
Sunday, July 20, marked 45 years since the United States put the first two astronauts safely on the moon. The cost for the Mercury, Gemini and Apollo programs was more than $25 billion at the time more like $110 billion in today’s world. The ensuing U.S. space efforts have cost an additional $196 billion for the shuttle and $50 billion for the space station. NASA’s total inflation-adjusted costs have been more than $900 billion since its creation in 1958 through 2014 (more than $16 billion per year). Looking back, have we gotten our money’s worth from the investment?
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A race car starts from rest and speeds up uniformly to the right until it reaches a maximum velocity of 60m/s^2
What is the acceleration of the race car?
Question:
A race car starts from rest and speed up uniformly to the right until it reaches a maximum velocity of 60m/s in 15 secs
Answer:
4m/s²
Explanation:
The acceleration of a body in uniform motion can be found by using one of the equations of motion as follows;
v = u + at ------------------(i)
Where;
v = final velocity of the body
u = initial velocity of the body
a = acceleration of the body
t = time taken for the motion
From the question, the body is the race car and has the following:
v = 60m/s²
u = 0 [since the car starts from rest]
t = 15 secs.
Now, substitute these values into equation(i) as follows;
60 = 0 + a(15)
60 = 15a [Divide through by 15]
[tex]\frac{60}{15}[/tex] = [tex]\frac{15a}{15}[/tex]
a = 4
Therefore, the acceleration of the race car is 4m/s²
A student leaves his house and walks 4 m east to friend's house, and then turns and walks 7 m west to the library in 120 seconds. Determine the student's average velocity for his entire walk.
Answer:
v_average = -0.025 m / s
the minus indicates that the velocity is to the west.
Explanation:
For this exercise we use the definition of average velocity
v_average = (x₂-x₁) / Δt
Let's keep in mind that the velocity is a vector, so the displacement is
x₂ - x₁ = 4 - 7 = -3
the minus indicates that the shift is to the west.
Let's calculate
v_average = -3 / 120
v_average = -0.025 m / s
the minus indicates that the velocity is to the west.
What is the final speed of a lion initially running at a speed of 30 m/s, if it accelerates at
a rate of 3 m/s3 for 5 seconds?
A perfect bouncy ball would continue bouncing the same height forever. But in reality, the ball stops bouncing because energy is "lost" to ...
A.sound energy
B.compression of the ball
C.heat energy absorbed by the ball
D.all answers are true
Answer:
D. all answers are true
The ball stops bouncing because energy is to sound energy, compression of the ball, and heat energy absorbed by the ball. Thus, the correct option is D, i.e. all of the above.
How energy is lost in a physical state?The law of conservation of energy, it states that energy can neither be created nor be destroyed in any physical state, although it may get transformed into another form.
The same principle is followed by the bouncing ball. In a closed system, its energy is never lost but it may get transformed into sound energy, heat energy which is absorbed by the ball, and compression which stimulates the process of bouncing the ball.
It is a principle of physical science that due to some characteristics the energy may be transformed into other form.
Therefore, the correct option is D, i.e. all of the above.
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If a train (travelling from Albuquerque to Atlanta) is moving 33.9 meters per second when it accelerates at -2.02 m/s^2 for 1.01 seconds, what is the final velocity
Answer:
The final velocity is 31.86 m/s.
Explanation:
The final velocity can be found using the following equation:
[tex] V_{f} = V_{0} + at [/tex]
Where:
[tex]V_{f}[/tex] is the final velocity =?
[tex]V_{0}[/tex] is the initial velocity = 33.9 m/s
a is the acceleration = -2.02 m/s²
t is the time = 1.01 s
[tex] V_{f} = V_{0} + at = 33.9 m/s + (-2.02 m/s^{2})*1.01 s = 31.86 m/s [/tex]
Therefore, the final velocity is 31.86 m/s.
I hope it helps you!
Why ultrasound is useful in medical field???
Answer:
It allows you to see fetuses before they are born.
Explanation:
because it has many helpful measures....
it helps in breaking and crushing the kidney stones...due to its high frequency....
If you add 50.0 mL of water to a beaker containing 22 mL of water, then how much water do you have in the beaker?
Answer:
72 mL
Explanation:
if you add 50.0 mL of water to a beaker containing 22 mL of water, then the total in the beaker is 50.0 + 22 = 72 mL
Which of the following options correctly describe electromagnetic radiation? Select all that apply. Particles of electromagnetic radiation exhibit wave behavior. A particle of electromagnetic radiation is called a quantum. All electromagnetic radiation has the same frequency. Electromagnetic radiation includes visible light. The specific amount of energy a particular photon possesses is called a quantum.
Answer:
Particles of electromagnetic radiation exhibit wave behavior
Electromagnetic radiation includes visible light
The specific amount of energy a particular photon possesses is called a quantum
Explanation:
Electromagnetic waves propagate through space perpendicularly to a oscillating magnetic and electric field producing it. Both of these fields oscillates perpendicular to one another, and to the direction of propagation of the wave.
Electromagnetic waves exhibit both wave and particle light behaviors, this phenomenon is known as the wave-particle duality.
Visible light is part of the broad spectrum of waves in the electromagnetic wave spectrum. And each particle of an electromagnetic wave is known as a photon, and they carry energy in discrete amounts called quantum.
Electromagnetic radiation occurs when electric and magnetic fields emit radiations that travel in waves. Given this explanation, the options that correctly describe electronic radiation are;
Particles of electromagnetic radiation exhibit wave behavior.The specific amount of energy a particular photon possesses is called a quantum. Electromagnetic radiation includes visible light.Electromagnetic radiation is used to explain the disturbance that occurs when the electric and magnetic fields travel at the speed of light.
There are different frequencies of radiation that are emitted in the process. Some have high and low energies.
The radio waves, ultraviolet rays, and visible light are all examples of electromagnetic radiation
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Place thermometers near the edge of the table for easy retrieval.
True
True
False
A cruise took 6 hours to fulfill its trip. It travelled at an average
speed of 160 km/h for the first 2 h 15 min. For the remaining
journey, it travelled at an average speed of 180 km/h. What was
the total distance of the journey?
Answer: 1035
Explanation:
Jim rode at an average speed of 12mph in 2 hours the he walked at an average of speed of 3 mph 0.5 hours what was the total distance covered by Jim
Answer:
12mph in 2hrs and 3mph in 0.5hrs the total distance would be 12*2 and 3*0.5 which would be 24 and 1.5 so we add those 24+1.5= 25.5. The answer would be 25.5
What is the power of 10 when 0.00503 is written in scientific notation
It's important to match your exercise shoes with the type of exercise in which you will be participating.
Answer:
True
Explanation:
Answer:
True is the correct answer
Explanation:
i took the test
Two teams are playing tug of war. Team A pulls to the right with a force of 450 N. Team B pulls to the left with a force of 415 N.
Answer:
Two teams are playing tug of war. Team A pulls to the right with a force of 450 N. Team B pulls to the left with a force of 415 N
Answer:
A. 35 N to the right.
EXPLANATION: 450 is going to the right so you subtract what is going against it. Which gives you 35. And because 450 is bigger than 415, it'll be going to the right.
A substance has density ρ, mass m, and volume V. If the volume is tripled, what is the new mass?
Since the density of the substance is ρ (rho),
==> every cm³ of this substance has ρ grams of mass.
Then
==> V cm³ of it has ρV grams of mass. That's ' m '.
and
==> 3V cm³ of it has 3ρV grams of mass. That's ' 3m '.
on, Inc., publishing as pe
6. Circle the letter before each element that is a gas at room temperature.
a. carbon
c. mercury
d. nitrogen
b. oxygen
What teaching methods help you the most (direct instruction, watching videos, teaching others) and why?
Explanation:
for me its teaching others. I find it really helpful to go over something then recite all the info to my mum or sister after without looking at notes to see how much I could remember
Read the excerpt from "Introduction to Poetry" by Billy Collins. or walk inside the poem's room and feel the walls for a light switch. How does this metaphor reveal Collins’s message? The metaphor suggests that poetic themes are serious and dark. The metaphor suggests that readers should explore poems in depth. The metaphor insists that readers should move about while reading. The metaphor insists that one must know the poet to understand the poem.
Answer:
d
Explanation:
hi
Answer:
the answer is b The metaphor suggests that readers should explore poems in depth.
Explanation:
I got it right
Which of the following is not an essential feature of scientific explanations? a. They must be subject to testing. b. They strictly pertain to the physical world. c. Their validity is judged based on objective observations. d. Once supported by observation, they can be viewed as a fact
Answer:b
Explanation:
The correct option is b.
The following are the essential feature of the scientific explanations:
It should be subjected to the testing. The validity should be judged depend upon the objective observations. Once the observation is supported afterwards it should be viewed as fact.Learn more: brainly.com/question/17429689