What is the instantaneous velocity of a freely falling object 11 s after it is released from a position of rest
Answer:
v= -107.8 m/s
Explanation:
Since the object is in free fall, this means that is moving at an accceleration equal to the one due to gravity.Since it starts at rest, we can apply the definition of acceleration, rearranging terms as follows:[tex]v_{f} = v_{o} + a*t = a*t = -g*t = 9.8m/s2*11s = -107.8 m/s (1)[/tex]
(Assuming as positive the upward direction)A flywheel of mass 182 kg has an effective radius of 0.62 m (assume the mass is concentrated along a circumference located at the effective radius of the flywheel).
(a) How much work is done to bring this wheel from rest to a speed of 120 rev/min in a time. interval of 30.0 s?
(b) What is the applied torque on the fly-wheel (assumed constant)?
Answer:
A)5524J,
B) 29.2Nm
Explanation:
This question can be treated using work- energy theorem
Work= change in Kinectic energy
W= Δ KE
Work= difference between the final Kinectic energy and intial Kinectic energy.
We know that
Kinectic energy= 1/2 mv^2 .............eqn(1)
This can be written in term of angular velocity, as
KE= 1/2 I
Which ray diagram demonstrates the phenomenon of absorption?
An illustration with a vector pointed right going through an opening in a boundary and splitting into 3 vectors. One up and to the right, one straight and one down to the right.
An illustration with a vector pointed right going through an opening in a boundary and turning into a transverse wave on the other side.
An illustration with a vector striking a boundary at an angle and a second vector coming off the boundary at the exact same angle.
Answer:
B
Explanation:
on edge
The illustration with a vector pointed right going through an opening in a boundary and turning into a transverse wave on the other side demonstrates the phenomenon of absorption, so, option B is correct.
What is absorption?Absorption, in wave motion, is the process by which a wave's energy is transferred to matter when the wave travels through it. The energy of an electromagnetic, acoustic, or other wave is related to the square of its amplitude, which is the maximum displacement or movement of a point on the wave.
The amplitude of a wave continuously diminishes as it travels through a substance. The medium is described as being transparent to a specific type of radiation if just a tiny portion of the energy is absorbed, whereas it is described as opaque if all the energy is lost.
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A 50kg refrigerator is being moved across a kitchen floor with an applied force of
300N. There is a known friction force of 50N acting against the motion of the
refrigerator.
What was the acceleration of the refrigerator? [ Select ]
m/s2
Answer:
5m/s²
Explanation:
Given parameters:
Mass of refrigerator = 50kg
Applied force = 300N
Frictional force = 50N
Unknown:
Acceleration of the refrigerator = ?
Solution:
To solve this problem:
Net force = m x a
m is the mass
a is the acceleration
Net force = Applied force - Frictional force
300 - 50 = 50 x a
250 = 50 x a
a = 5m/s²
A ball is thrown vertically upward from the top of a 100 foot tower, with an initial velocity of 10 ft/sec. Its position function is s(t)=−16t2+10t+100.
a. What is its velocity in ft/sec when t = 2 seconds? (Solve by using instantaneous rate.)
b. Determine the equation of a line, in slope-intercept form, that passes through the points (5, 6) and (10, 2).
Answer;
-54ft/s
y = -4/5 x + 10
Explanation
Given the position of an object expressed by the function
s(t)=−16t²+10t+100
Velocity is the change in position with respect to time
v(t) = ds(t)/dt
v(t) = -32t + 10
When t = 2
v(2) = -32(2)+10
v(2) = -64+10
v(2) = -54
Hence the velocity of the object is -54ft/s
b) The standard equation of a line in point slope form is expressed as;
y = MX+c
M is the slope
c is the y-intercept
Given the coordinate (5, 6) and (10, 2)
M = 2-6/10-5
M = -4/5
Get the y-intercept
Substitute m = -4/5 and any point say (5,6) into the expression y = mx+c
6 = -4/5 (5) + c
6 = -4+c
c = 6+4
c = 10
Get the required equation
Recall that: y = mx+c
y = -4/5 x + 10
Hence the equation of a line, in slope-intercept form is y = -4/5 x + 10
True or False do Eclipses, tides, season, and moon phases ALL have to do with the positions of the Earth, Sun, and Mars.
Which of the following does NOT describe a major function of the reproductive system?
a. produce sex cells
b. produce hormones
c. produce waste products
d. produce offspring
Which statement best explains how wave one compares with wave 2
A. wave one has louder sound
B. wave one has softer sound
C. wave one had higher pitch
D. wave one has a lower pitch
Answer:
D. wave one has a lower pitch
Explanation: because The sound an object makes changes depending on how fast it is vibrating. When an object vibrates quickly, high-pitched sounds are heard. Low-pitched sounds come from things that vibrate more slowly.
A 4 kg object moving to the left collides with and sticks to a 3 kg object moving to the right. Which of the following is true of the motion of the combined objects immediately after the collision?
a. They must be moving to the left.
b. They must be moving to the right.
c. They must be at rest.
d. The motion cannot be determined without knowing the speeds of the objects before the collision.
Answer:
D. The motion cannot be determined without knowing the speeds of the objects before the collision.
Explanation:
This question is tricky! We know the object moving to the left has a greater mass than the one moving to the right. We'd assume they would move to the left because the leftwards object has a greater mass, right?
Not. So. Fast.
We can solve for the objects' final velocity using the formula for momentum, m₁v₁ + m₂v₂ = (m₁ + m₂)v .
Now here's where the trap is sprung: we don't think about the equation. This shows that the final velocity of the objects and the direction depends on both the mass of the objects and their initial velocity.
Basically, what if the 3 kg object is moving at 1 m/s and the 4 kg object is moving at –0.5 m/s? The objects would move to the right after the collision!
Do we know the velocity of these objects? No, right?
That means we can't determine the direction of their motion unless we know their initial, pre-collision velocity. This question is tricky because we look at the 4 kg vs. 3 kg and automatically assume the 4 kg object would dictate the direction of motion. That's not true. It depends on velocity as well.
I hope this helps you! Have a great day!
how much work is required to make a 1400 kg car increase its speed from 10 m/s to 20 m/s?
Answer:
7000J
Explanation:
Given parameters:
Mass of car = 1400kg
Initial speed = 10m/s
Final speed = 20m/s
Unknown:
Amount of work done = ?
Solution:
In this problem, the amount of work done is the same as the change in kinetic energy of the body.
So;
Work done = Final kinetic energy - initial kinetic energy
Kinetic energy = [tex]\frac{1}{2}[/tex] m v²
Work done = [tex]\frac{1}{2}[/tex] m(V²f - V²i )
m is the mass
vf is the final velocity
vi is the initial velocity
Work done = [tex]\frac{1}{2}[/tex] x 1400 x (20 - 10) = 7000J
The speed of sound in air is 340 m/s. A sound wave that is traveling through air has a wavelength of 17 m. What is the frequency of this sound? *
Answer:
Assuming the speed of sound in air is 345 m/s, determine the wavelength of this infrasonic sound wave. Let λ = wavelength. Use v = f • λ where v = 345 m/s and f = 10 Hz.
Explanation:nothing is my explanation lol
How do I solve this problem please help
Answer:
som,eythiung did cant wait
Explanation:
ya so i texted maria and she said i con c()me over so letyeyey yeah betty letty
PAINN I MISS JUOICE WORLDD PAINNNN
Assuming no friction, how does the initial gravitational potential energy of
the marble on a downward slope compare to the final kinetic energy?
a) they are the same
b) the initial gravitational potential energy is greater than the final kinetic energy
c) the initial gravitational potential energy is less then the final kinetic energy
Answer:
a) They are the same.
Explanation:
Assuming no friction, there should be no energy transfer and thus the Law of Conservation of Energy says:
[tex]PE=KE,\\mgh=\frac{1}{2}mv^2[/tex]
These types of problems also disregard any air resistance the surface of the object may cause. Therefore, no energy is transferred and from the Law of Conservation of Energy, [tex]100\%[/tex] of energy is preserved.
Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.69 times a second. A tack is stuck in the tire at a distance of 0.331 m from the rotation axis. Noting that for every rotation the tack travels one circumference, find the tack's tangential speed.
Answer:
the tack's tangential speed is 5.59 m/s
Explanation:
Given that;
R = 0.331 m
wheel rotates 2.69 times a second which means, the wheel complete 2.69 revolutions in a second, so
ω = 2.69 rev/s × 2π/1s = 16.9 rad/s
using the relation of angular speed with tangential speed
tangential speed v of the tack is expressed as;
v = R × ω
so we substitute
v = 0.331 m × 16.9 rad/s
v = 5.59 m/s
Therefore, the tack's tangential speed is 5.59 m/s
William Gilbert used a terella in an attempt to explain _____.
why like poles of a magnet repel
why unlike poles of a magnet attract
why compasses point toward the north and south poles of the earth
the properties of lodestone
Answer:
why compasses point towards the north and south poles of the earth.
Explanation:
hope it helps!!
Show that the speed of a moving particle over a time interval is constant if and only if its velocity and acceleration vectors are perpendicular over the time interval.
Answer:
[tex]|v|(t)=\sqrt{v_{x}^{2}(t)+v_{y}^{2}(t)+v_{z}^{2}(t)}=C[/tex]
[tex]2v(t)\cdot \frac{dv(t)}{dt}=0[/tex]
[tex]v(t)\cdot a(t)=0[/tex]
Explanation:
Let's start with the definition of a constant velocity.
If the velocity magnitude, in three dimensions, is a constant value (C) we have a constant velocity, which means.
[tex]|v|(t)=\sqrt{v_{x}^{2}(t)+v_{y}^{2}(t)+v_{z}^{2}(t)}=C[/tex]
Now, we know that the dot product between v(t) and v(t) is the |v|².
[tex]v(t)\cdot v(t)=|v|^{2}(t)[/tex]
If we take the derivative whit respect to time in both sides of this equation we will have:
[tex]\frac{d}{dt}(v(t)\cdot v(t))=\frac{d}{dt}|v|^{2}(t)[/tex]
We apply the product rule on the left side and the right side will zero because the derivative of a constant is 0.
[tex]\frac{dv(t)}{dt}\cdot v(t)+v(t)\cdot \frac{dv(t)}{dt}=0[/tex]
[tex]2v(t)\cdot \frac{dv(t)}{dt}=0[/tex]
We know that dv(t)/dt = a(t) (using the acceleration definiton)
Therefore, we conclude:
[tex]v(t)\cdot \frac{dv(t)}{dt}=0[/tex]
[tex]v(t)\cdot a(t)=0[/tex]
If the dot product is 0, it means that v(t) and a(t) are orthogonal.
I hope it helps you!
. Which of the statement below about the magnetic
properties of iron and steel is correct?
A. Both iron and steel are equally magnetized and
demagnetized
B. Iron is more easilymagnetized and demagnetized
than steel.
C. Steel is more easily magnetized and demagnetized
than iron
D. Iron is more easily magnetized than steel but steel is
more easily demagnetized than iron.
Answer:
D. Iron is more easily magnetized than steel but steel is more easily demagnetized than iron.
Waves in the ocean are tearing apart the shoreline. Which of the following two Earth Systems are interacting with each other.
Answer:
the Indian Ocean on 26 December 2004. This event claimed 227,898 dead and missing from 14 countries. The difference in mortality rates between these tsunamis reflects, in part, the benefits of understanding how tsunami waves are generated and move, and educating citizens to make scientifically
sound and potentially life-saving decisions.
A tsunami is a series of rapidly propagating, shallow-water ocean waves that develops when a submarine earthquake, landslide, or volcanic eruption displaces a large volume of water. Powerful earthquakes, with magnitudes of 9 or greater, caused both the 2004 and 2011 tsunamis. The earthquakes resulted from the movement of large tectonic plates. The 11 March 2011 earthquake occurred at 32 km (20
mi.) deep in Earth’s crust about 130 km (81 mi.) east of the city of Sendai. This location is on the boundary between two tectonic plates—the Pacific plate to the east and North American plate to the west. This
boundary fractured, releasing energy that was transmitted through the rocks and elevated portions of the
ocean floor. This drastic movement transmitted energy to the overlying ocean water, which generated
tsunami waves that radiated outward. The waves washed over the nearby coastlines and were felt around
the globe within hours (Figure 1.1).
Explanation:
Answer:
I believe Geosphere (lithosphere) and Hydrosphere
Explanation:
I hope it's right if not please notify me.
In 1800, Herschel wondered if the different colors of the rainbow were equal in brightness and heat. He used a prism to separate sunlight into it's different colors and thermometers to measure how much "heat energy" was included with each color. He also measured how much "brightness" was associated with each color. He noticed a "brightness" peak at the middle of the spectrum. Red and violet had the least amount of brightness with a "peak" at green and yellow. But for "heat energy", violet had the least and the amount of heat climbed more and more and showed no sign of a "peak" .
His observations supported the idea that neither Brightness nor heat were evenly distributed between the different colors. Some colors had more brightness (green and yellow) and a different color had the most heat (red).
But this lead to a new question. Did the "heat" exist even where there was no visible light and did it peak at wavelengths less than red. He did another set of experiments and found this to be the case. He again used a prism to separate sunlight into the colors of the rainbow. These colors were cast on a sheet of paper and a thermometer could be moved from one color to the next to measure the amount of heat. But this time, he moved the thermometers beyond the red light and made measurements on the paper where there was no visible light. He found the maximum amount of heat at wavelengths longer visible red light.
When Herschel selected where to place his thermometer and then measure the temperature, which variable was the Independent variable.
Question options:
A. The time of day
B. The month of the year
C. the temperature rise
D. the placement of the thermometer
Answer:
D.
Explanation:
im guessing.
PLEASSEE HELP MEEE WITHH THESEEE
Forty-five cm are equivalent to how many m? State your answer using Scientific Notation.
a
45 x 10^-2 m
b
4.5 x 10^-2 m
c
.45 x 10^-2 m
d
0.45 x10^-2 m
The radius of the earth is 6378 km. What is the diameter of the earth in meters? Use scientific notation to state your answer.
a
6378 x 10^3 m
b
.6378 x 10^3 m
c
6.378 x 10^6 m
d
6.378 x 10^3 m
In an experiment, you find the mass of a cart to be 250 grams. What is the mass of the cart in kilograms?
a
2.5 x 10^3 kg
b
2.50 x 10^3 kg
c
2.50 x 10^-3 kg
d
2.5 x10^-3 kg
Answer:
Q1: (a)
[tex]1cm \: = 10 {}^{ - 2}m[/tex]
so
[tex]45 \times {10}^{ - 2} m[/tex]
Q2:
[tex]1km = 10 {}^{3} m \\ 6378km \times {10}^{ 3} [/tex]
this is the radius in meter
diameter = 2r
in this i don't know which choice is the right answer
Q3:
[tex]1gram = \: {10}^{ - 3} kg[/tex]
so
[tex]250 \times {10}^{ - 3} = 2.5 \times {10}^{ - 1} kg[/tex]
again there is no correct answer
I NEED HELP ASAP PLEASE!
Study the scenario.
Boiling water is poured into a Styrofoam cup and a metal cup. You pick up and hold the metal cup and the Styrofoam cup. The metal cup burns your fingers, but you can hold the Styrofoam cup without experiencing any pain.
The difference in the rate at which these two materials transfer thermal energy throughout the cups is known as __________.
evaporation
electrical energy
thermal conductivity
condensation
Answer: thermal conductivity
The difference in the rate at which these two materials transfer thermal energy throughout the cups is known as thermal conductivity.
What is thermal conductivity?It is the rate where the heat is to be transferred from conduction via the cross section area of the unit with respect to the material at the time when the temperature should be gradient and existed with the perpendicular to the area.
Also, in this, two material is to be transferred via the thermal energy with the help of cups.
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An object of mass 5kg travels in the positive direction with a speed of 1ms1ms. The object collides with a second object that exerts an average net force over an interval of time such that the 5kg object comes to rest. Which of the following best predicts the change in momentum for the 5kg object?
a. The change in momentum is in the negative direction.
b. The change in momentum is in the positive direction.
c. The change in momentum is zero.
d. The direction of the change in momentum cannot be determined without knowing the value of the average force and time in which the force is exerted.
Answer:
Explanation:
The change in momentum is in the negative direction.
WILL MARK BRAINLIEST Why do we see sedimentary rocks more often than igneous and metamorphic rocks?
O Because they are extrusive
O Because they are intrusive
O because they are the rocks found in the ocean
O because they are the rocks that line the surface of our planet
Answer:
because they are the rocks that line the surface of our planet
Explanation:
We see sedimentary rocks more than other rock types because they are the rocks that line the surface of our planet.
Sedimentary rocks typically form the earth cover due to the way they are formed.
These rocks are produced by the weathering, transportation and deposition of sediments within a basin. In this basin, the sediment is lithified and converted to sedimentary rocks. These processes are driven by the external heat engineTherefore, it is confined to the surface. Igneous and metamorphic rock's processes are confined to the subsurface.
Can a single atom be considered a molecule?
A:only if the atom is found in water
B:no, it takes two or more atoms bonded to create a molecule
C:only if it is an oxygen atom floating in the air
D:yes, all atoms are made up of many different molecules
A 100 V battery is connected across a
resistor and causes 5 mA current to flow.
Determine the resistance of the resistor.
If the voltage is now reduced to 25 V,
what will be the new value of the current
flowing?
1 mA = 0.001 A
Therefore, 5 mA = 0.001 * 5
=0.005 A
Resistance = voltage / current
= 100 / 0.005
= 20000 ohms
Current = voltage / resistance
= 25 / 20000
= 0.00125 A (or) 1.25 mA
A truck pushes a mound of dirt 5 meters with a force of 75 newtons. How much
work has been done?
Answer:
[tex]375\:\mathrm{N}[/tex]
Explanation:
Work is given by the equation [tex]W=F\Delta x[/tex]. Plugging in given values, we get:
[tex]W=75\cdot 5=\fbox{$ 375\:\mathrm{N}$}[/tex].
A U-tube manometer is used to measure the pressure at the stagnation point of a model in a wind tunnel. One side of the manometer goes to an orifice at the stagnation point; the other side is open to the atmosphere ( Fig. P1.24 ). If there is a difference of 3.0 cm in the mercury levels in the two tubes, what is the pressure difference in N>m2 .
Answer:
ΔP = 3.98 10³ Pa
Explanation:
We use that the pressure is given
P = ρ g y
where ρ is the density of mercury (ρ = 13534 kg / m³) and y the height of the column
In this case, to measure the pressure, a line is drawn at the lowest point of the mercury column, on the right side of the U-shaped tube, for this point the pressure on both sides of the tube is the same
ΔP = P_l{eft} - P_{right}
ΔP = (P_a + P) - P_a
done P is the gauge pressure on the left side and P_a is the atmospheric pressure
ΔP = ρ g h
let's calculate
ΔP = 13534 9.8 0.03
ΔP = 3.98 10³ Pa
remember that [Pa] = [N / m²]
Why is damage from sound waves is an issue on the launchpad but not in the air
(I would have done more points for answering but I'm almost out sry. just pls answer and help.)
The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.
Closeness to the Sound Source: When a rocket is fired on the launchpad, it creates a tremendous amount of noise in proximity to the nearby equipment and structures.
When a rocket is launched, concentrated sound waves are created that can seriously harm neighboring structures, especially if such structures are not built to handle such strong vibrations. In contrast, once a rocket is in the air, the sound waves spread out and become less forceful as they travel through the atmosphere, decreasing the possibility that they may cause harm.
Reflection and Amplification: The launchpad environment can serve as an echo chamber for sound waves because of its huge, solid structures.
Hence, The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.
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A car is traveling at speed of 18.6m/s and entering a 12m wide intersection when the light has 0.582seconds More Time remain yellow.
a) what does the acceleration of the car needed to be so that its infront is out of the intersection when the light turns red?
Answer:
6.94 m/s²
Explanation:
Given that:
Initial Velocity (u) = 18.6 m/s
Time, t = 0.582
S, distance = 12 m
S = ut + 0.5at²
12 = (18.6 * 0.582) + 0.5(a)(0.582²)
12 = 10.8252 + 0.169362a
12 - 10.8252 = 0.169362a
1.1748 = 0.169362a
a = 1.1748 / 0.169362
a = 6.9366209
a = 6.94 m/s²
Hence, acceliofbthe car should be 6.94 m/s²
According to Newton’s second law of motion, when an object is acted on by an unbalanced force, how will that object respond?
It will stop moving.
It will accelerate.
It will decrease speed.
It will increase velocity.
It will accelerate. A force of magnitude F exerted on an object of mass m applies an acceleration a according to
F = m a
Remember that force and accleration are vector quantities, so the object's acceleration would point in the same direction as the applied force. The other choices describe some possible outcomes, but
• it the object starts in motion, it can only stop moving if the force opposes the motion and acts in the opposite direction. The object would eventually stop, but only for an instant before changing direction and starting to move again. Consider a ball being thrown directly upward, reaching its highest point, then falling again.
• its speed (which is a scalar quantity) would only decrease if the object starts in motion and is slowed down. But if it starts at rest, its speed can only increase. Consider a ball being dropped from some height and gaining speed as it falls.
• its velocity will certainly change, but can only increase if the object is at rest, or if it's already in motion and the force points in the same direction.
Answer:
It will accelerate.
Explanation:
i go to K12