Answer: -49m/s.
Explanation:
As the rock only falls, we will assume that the initial vertical velocity is zero.
We neglect the air friction, so the only force acting on the rock is the gravitational force, this means that the acceleration is -g = -9.8m/s^2.
Then we can write:
a(t) = -9.8m/s^2
To write the velocity of the rock, we must ingrate over time and get:
v(t) = (-9.8m/s^2)*t + v0
where v0 is the initial vertical velocity, and as we said above, v0 = 0m/s
Then the vertical velocity as a function of time is:
v(t) = (-9.8m/s^2)*t
Now, the question is:
"...If a rock falls for 5 seconds near the surface of the earth and with no air friction, it will reach a velocity of..."
Then we need to evaluate the velocity equation in t = 5 seconds.
v(5s) = (-9.8m/s^2)*5s = -49m/s.
At any given time in space, how much of
the moon is lit by the sun?
PLEASE ANSWER QUICKLY!!!
Answer: 50%
Explanation: The sun and the moon go around Earth and The sun is way bigger than the moon so 50% of the sun lights up the moon at night
Answer:
50%
Explanation:
What is the critical angle of a light beam passed from a medium (n=2) to a medium (n=1.2)?
Answer:
θ_c = 36.87°
Explanation:
Index of refraction for index medium; n_i = 2
Index of refraction for Refractive medium; n_r = 1.2
Formula to find the critical angle is given;
n_i(sin θ_c) = n_r(sin 90)
Where θ_c is critical angle.
Thus;
2 × (sin θ_c) = 1.2 × 1
(sin θ_c) = 1.2/2
(sin θ_c) = 0.6
θ_c = sin^(-1) 0.6
θ_c = 36.87°
The data table shows how the amplitude of a mechanical wave varies with
the energy it carries. Analyze the data to identify the mathematical
relationship between amplitude and energy. Use your equation to find the
energy if the amplitude is 6 units.
Amplitude
Energy
1 unit
2 units
2 units
8 units
3 units
18 units
4 units
32 units
Answer:
162
Explanation:
When the amplitude of the wave is 8 units, the corresponding energy of the wave is 128 units. Therefore, option C is correct.
What do you mean by an amplitude ?The term amplitude is defined as the maximum distance moved by a point on a vibrating body or wave calculated from its equilibrium position.
We have given,
first amplitude, A = 1, corresponding energy = 2
second amplitude, A = 2, corresponding energy = 8
The energy of a string at a given amplitude is calculated as follows;
E ∝ A²
Energy varies as the square of the change in amplitude.
If amplitude of one has energy of two
Amplitude of 2 (double of 1)
= ( 2 x 2 ) = 4 x 2
= 8 4 times the energy at amplitude of 1.
Then for 8 units of amplitude change
8 x 8 = 64 x 2
= 128
Thus, When the amplitude of the wave is 8 units, the corresponding energy of the wave is 128 units, option C is correct.
To learn more about an amplitude, follow the link;
https://brainly.com/question/15930409
#SPJ2
Your question is incomplete, most probably your question was
The data table shows how the amplitude of a mechanical wave varies with the energy it carries. Analyze the data to identify the mathematical relationship between amplitude and energy. Use your equation to find the energy if the amplitude is 8 units.
Amplitude
1
2
3
4
energy
2
8
18
32
A.66 units
B. 108 units
C. 128 units
D. 88 units
PLEASE HELP!!!
If the current in a wire is 2.0 amperes and the potential difference across the wire is 10.0 volts, what is the resistance of the wire?
When examining evidence, why might investigators want to be more careful examining chemical properties than physical properties.
Answer:
Please find the answers in the explanation
Explanation:
In examination of any scientific observation, some experiments may be needed to be carried out.
When examining evidence, the investigators might want to be more careful examining chemical properties than physical properties because anything that involve chemical reaction are irreversible. While physical one can be reversible.
Also, reaction can easily take place when examining the chemical properties of some substances.
It is seldom for reaction to take place with physical one.
there can be some complications and danger with chemical properties but less complication and danger with physical one.
Therefore, the investigators will want to be more careful when examining evidence on chemical properties than physical properties due to the given reasons above.
A 2000 kg car moves along a horizontal road at speed vo
15.9 m/s. The road is
wet, so the static friction coefficient between
the tires and the road is only pls 0.105 and
the kinetic friction coefficient is even lower,
= 0.0735.
The acceleration of gravity is 9.8 m/s2.
What is the shortest possible stopping dis-
tance for the car under such conditions? Use
g= 9.8 m/s² and neglect the reaction time of
the driver.
Answer in units of m.
Answer:
The shortest possible stopping distance of the car is 175.319 meters.
Explanation:
In this case we see that driver use the brakes to stop the car by means of kinetic friction force. Deceleration of the car is directly proportional to kinetic friction coefficient and can be determined by Second Newton's Law:
[tex]\Sigma F_{x} = -\mu_{k}\cdot N = m \cdot a[/tex] (Eq. 1)
[tex]\Sigma F_{y} = N-m\cdot g = 0[/tex] (Eq. 2)
After quick handling, we get that deceleration experimented by the car is equal to:
[tex]a = -\mu_{k}\cdot g[/tex] (Eq. 3)
Where:
[tex]a[/tex] - Deceleration of the car, measured in meters per square second.
[tex]\mu_{k}[/tex] - Kinetic coefficient of friction, dimensionless.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
If we know that [tex]\mu_{k} = 0.0735[/tex] and [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], then deceleration of the car is:
[tex]a = -(0.0735)\cdot (9.807\,\frac{m}{s^{2}} )[/tex]
[tex]a = -0.721\,\frac{m}{s^{2}}[/tex]
The stopping distance of the car ([tex]\Delta s[/tex]), measured in meters, is determined from the following kinematic expression:
[tex]\Delta s = \frac{v^{2}-v_{o}^{2}}{2\cdot a}[/tex] (Eq. 4)
Where:
[tex]v_{o}[/tex] - Initial speed of the car, measured in meters per second.
[tex]v[/tex] - Final speed of the car, measured in meters per second.
If we know that [tex]v_{o} = 15.9\,\frac{m}{s}[/tex], [tex]v = 0\,\frac{m}{s}[/tex] and [tex]a = -0.721\,\frac{m}{s^{2}}[/tex], stopping distance of the car is:
[tex]\Delta s = \frac{\left(0\,\frac{m}{s} \right)^{2}-\left(15.9\,\frac{m}{s} \right)^{2}}{2\cdot \left(-0.721\,\frac{m}{s^{2}} \right)}[/tex]
[tex]\Delta s = 175.319\,m[/tex]
The shortest possible stopping distance of the car is 175.319 meters.
A scientist measures the growth of a bamboo plant over time. The table
below shows the results.
Time (hours)
Height (cm)
10
1.2
20
1.5
30
1.8
40
2.1
50
2.4
60
2.8
How tall was the bamboo plant after 20 hours?
Answer:the answer is 1.5
Explanation: I know bc I just had that question on a test.
F all of the energy in a falling object's gravitational potential energy store is transferred to its kinetic energy store by the time it lands, then the relationship shown below can be used. Which of the four options below it correctly shows how this relationship can be expressed in terms of height, h?
Answer:
The options are not shown, so let's derive the relationship.
For an object that is at a height H above the ground, and is not moving, the potential energy will be:
U = m*g*H
where m is the mass of the object, and g is the gravitational acceleration.
Now, the kinetic energy of an object can be written as:
K = (1/2)*m*v^2
where v is the velocity.
Now, when we drop the object, the potential energy begins to transform into kinetic energy, and by the conservation of the energy, by the moment that H is equal to zero (So the potential energy is zero) all the initial potential energy must now be converted into kinetic energy.
Uinitial = Kfinal.
m*g*H = (1/2)*m*v^2
v^2 = 2*g*H
v = √(2*g*H)
So we expressed the final velocity (the velocity at which the object impacts the ground) in terms of the height, H.
A sock with a mass of 0.03 kg is stuck to the inside of a clothes dryer spins
around the drum once every 0.5 sec at a distance of 0.5 m from the center of
the drum. What is the linear speed if the sock could fly out?*
Answer:
15.71 m/s
Explanation:
We are given;
Time; t = 0.2 s
Radius; r = 0.5 m
The circumference will give us the distance covered.
Formula for circumference is 2πr
Thus; Distance = 2πr = 2 × π × 0.5 = π
Linear speed = distance/time = π/0.2 = 15.71 m/s
1. who was john locke?
2. what were his 3 big ideas?
3. what does each of his 3 big ideas mean?
What force is needed to move a barrel 45-m if 3600 J of work are accomplished?
Answer:
The answer is 80 NExplanation:
The force acting on the object can be found by using the formula
[tex]f = \frac{w}{d} \\ [/tex]
where
d is the distance
w is the work done
We have
[tex]f = \frac{3600}{45} \\ [/tex]
We have the final answer as
80 NHope this helps you
What is the velocity of a car that travels 200 meters In 8 seconds?
Answer:
25m/s
Explanation:
200m/ 8s =25m/s
The chart below represents the change in velocity for four different trains. Change in Velocity for four different trains, Train, Initial Velocity, Final Velocity, W, 60, 91, X, 39, 68, Y, 42, 70, Z, 65, 94 If it took 5.38 s for each train to reach the final velocity, which train had the smallest acceleration?
Answer:
Explanation:
Acceleration = (final velocity - initial velocity) / time
Acceleration of W = ( 91 - 60 ) / 5.38 = 5.76 m /s²
Acceleration of X = ( 68 - 39 ) / 5.38 = 5.39 m /s²
Acceleration of Y = ( 70 - 42 ) / 5.38 = 5.20 m /s²
Acceleration of W = ( 94 - 65 ) / 5.38 = 5.39 m /s²
So Train Y is the smallest acceleration.
Covert 1 mile to feet. Then convert to inches. Then covert to centimeters. How many centimeters are in a mile?
Answer:
160,934.4 cm or in other words *160,934*
Explanation:
1 mile = 5280 ft.
5280 ft. = 63360 in.
63360 in. = 160934.4
a) What is an atom?
b) What are the three sub-atomic particles of an atom
c) Where is the proton located?
d) Where is the neutron located?
e) Where is the electron located.
What is the charge of the electron? *
Answer:
A) basic units of matter
B) Protons, neutrons, electrons
C) In the nucleus
D) In the nucleus
E) Outside of the nucleus
Explanation:
Answer:
A-Atoms are the basic units of matter and the defining structure of elements.
B-Atoms are composed mainly of protons, neutrons, and electrons.
C and D-Protons and neutrons are found in the nucleus.
E-outside nucleus=eletron location,
Electrical charge is a fundamental aspect of matter. It has two different types called positive and negative (these are just conventional names, there’s nothing special about being positively charged vs. negatively charged). It has the peculiar property where like charges (two positive or two negative) will repel each other while two opposed charges (one each of positive and negative) will attract each other.
Hope this helps!
You push a desk with 245 N, but the desk doesn't move due to its friction with the ground. What is the magnitude of the friction force felt by the desk?
If the desk doesn't move, then it's not accelerating.
If it's not accelerating, then the net force on it is zero.
If the net force on it is zero, then any forces on it are balanced.
If there are only two forces on it and they're balanced, then they have equal strengths, and they point in opposite directions.
So the friction on the desk must be equal to your 245N .
What creates the solar wind?
Answer:
The solar wind is created by the outward expansion of plasma (a collection of charged particles) from the Sun's corona (outermost atmosphere). This plasma is continually heated to the point that the Sun's gravity can't hold it down. It then travels along the Sun's magnetic field lines that extend radially outward.
Which statement about two objects having the same momentum is true?
The product of mass X velocity is the same for both.
Mass and velocity are the same for both.
They both have the same mass.
They both have the same velocity.
Answer:
The product of mass X velocity is the same for both
Explanation:
The momentum of a body is the product of its mass and velocity.
Momentum = mass x velocity
Two objects having equal momentum will have the same for the product of their mass and velocity.
It is amount of motion a body can produce.A coal train in Montana starts from rest and accelerates at 2.5m/s^2 for 15 s.
Complete Question
A coal train in Montana starts from rest and accelerates at 2.5m/s^2 for 15 Find the trains maximum velocity
Answer:
The maximum velocity is [tex]v = 37.5 \ m/s [/tex]
Explanation:
From the question we are told that
The acceleration is [tex]a =2.5\ m/s^2[/tex]
The time for the acceleration is [tex]t = 15 \ s[/tex]
Generally from the kinematics equation
[tex]v = u + at[/tex]
here u is the initial velocity and the value is 0 m/s given that it started rom rest
[tex]v = 0 + 2.5 * 15[/tex]
[tex]v = 37.5 \ m/s [/tex]
How many minutes in 18 years? (Remember: 1 year = 365.25 days). Also, on these problems use a
bridge/table to organize your values
4.9671280 sec
4,9674280 min
9.467 280 sec
9 467280 min
answer:
in 18 years there are 9,467280 minutes
hope this helped! <3 i answered your question & hope you have a great day! if you wouldn't mind could you pls give me brainliest? (im trying to level up) thanks! :)
Can you please help me it’s due at 11:59 please
Answer:
1 is summer, 2 is most likely winter,3 is most likely summer, and 4 is fall
Explanation:
What is the force of an object with a mass of 30 kg that is free falling?
Answer:
F = 294.3 [N]
Explanation:
To solve this problem we must use Newton's second law which tells us that force is equal to the product of mass by acceleration. It is this particular case the acceleration is due to the gravitational acceleration since the body is in free fall.
Therefore we have:
F = m*g
where:
F = force [N]
m = mass = 30 [kg]
g = gravity acceleration = 9.81 [m/s^2]
F = 30*9.81
F = 294.3 [N]
what is the medium of the sound waves the student hears
Answer:
A
Explanation:
the air is the medium man
Answer:
the desk
Explanation:
I don't know what to do so first people to answer get 30 points
also tell me your favorite football team and hockey team
Answer:
seahawks, la kings
Explanation:
WH
Two forces are applied to a 3.0kg block on a
frictionless horizontal surface, as shown in the
diagram below
F1=25N
F2=ION
The apoeleration of the block 15
5.0 m/s2 to the left
2.0 m/s2 to the right
O 5.0 m/s2 to the left
6.0 m/s2 to the right
In the desert air, sound travels at 358 meters per second (m/s). In the polar air, sound travels at 330 meters per
second (m/s). What can you conclude from this information?
A - The speed of sound is constant.
B - Sound waves travel fastest in a vacuum.
C-The temperature of the air affects the speed of sound.
D-Sound waves travel at the same speed everywhere on Earth.
Please provide your answer below using CER
1. Claim: What is your choice for the correct answer?
2. Evidence: What evidence did you observe from the test-like question that made you decide on your answer?
3. Reasoning: Provide an elaboration on your evidence, possible prior knowledge about your claim.
Answer:
The correct option is;
C. The temperature of the air affects the speed of sound
Explanation:
The information given are;
The speed with which sound travels in the desert air = 358 m/s
The speed with which sound travels in the polar air = 330 m/s
The major difference between the desert air and the polar air is that the temperature of the desert air is hotter than the temperature of the air in the polar region. Therefore the speed of sound is affected by the air temperature.
The equation that gives the relationship of the speed of sound in air, [tex]v_{air}[/tex], to temperature is presented as follows;
[tex]v_{air} = 331\frac{m}{s} \times \sqrt{\dfrac{T_K}{273 K} } = 331\frac{m}{s} \times \sqrt{1 + \dfrac{T_{^{\circ}C}}{273 ^{\circ} C} }[/tex]
Which shows that the speed of sound in air, [tex]v_{air}[/tex], rises as the temperature of the air rises.
Where;
[tex]T_{^{\circ}C}[/tex] = The temperature of the air in degrees Celsius
[tex]T_K[/tex] = The temperature of the air in degrees Kelvin.
YOU ARE HUNGRY SO YOU WALK TO THE KITCHEN AND OPEN THE REFRIGERATOR DOOR. YOU NOTICE THAT THE LIGHT IS OFF AND THE FOOD IS COLD. YOU SEE THAT THE REFRIGERATOR IS PLUGGED IN THE WALL OUTLET. A MICROWAVE WHICH IS ON THE SAME ELECTRICAL OUTLET ALSO IS NOT WORKING.
MAKE A CLAIM, EVIDENCE, AND REASONING ABOUT ENERGY IN THE ABOVE SCENARIO
Explain and reason why the the moon rotates around the earth every lunar cycle
Pls explain ASAP
Best answer will be marked as BRAINLIEST✨
Why might using the speed of light to determine the length of the meter be
more reliable than using a measured distance around Earth?
Answer:ghjkdfrtghjExplanation:
A 3 kg rock is subject to the force of gravity for 8 s. What is the impulse?
Answer:
The impulse on the block due to force of gravity is 235.2 N.s
Explanation:
Given;
mass of the block, m = 3 kg
time of force of gravity action on the block, t = 8 s
Force of gravity on the block is given as;
F = mg
where;
m is mass of the block
g is acceleration due to gravity = 9.8 m/s²
F is the force of gravity
Substitute the given values and calculate F
F = mg
F = 3 x 9.8
F = 29.4 N
The Impulse on the block is given by;
J = Ft
J = 29.4 N x 8 s
J = 235.2 N.s
Therefore, the impulse on the block due to force of gravity is 235.2 N.s
