A particle moves along the x axis so that its velocity at time t is given by v(t)=
−(t + 1) sin(t2/2). At time t = 0, the particle is at position x = 1. Find the acceleration of the particle at time t = 4. Is the speed of the particle increasing at t = 4? Why or why not?
.
Answer:
a = 0.7267 , acceleration is positive therefore the speed is increasing
Explanation:
The definition of acceleration is
a = dv / dt
they give us the function of speed
v = - (t-1) sin (t² / 2)
a = - sin (t²/2) - (t-1) cos (t²/2) 2t / 2
a = - sin (t²/2) - t (t-1) cos (t²/2)
the acceleration for t = 4 s
a = - sin (4²/2) - 4 (4-1) cos (4²/2)
a = -sin 8 - 12 cos 8
remember that the angles are in radians
a = 0.7267
the problem does not indicate the units, but to be correct they must be m/s²
We see that the acceleration is positive therefore the speed is increasing
A plane starting from rest accelerates
to takeoff velocity of 75 m/s in 15
seconds. What was the plane’s
acceleration and how far did it travel
before takeoff?
Answer:
The acceleration is 5 m/s² and the distance is 562.5 m.
Explanation:
Given that,
Initial velocity of the plane, u = 0 (at rest)
Final speed, v = 75 m/s
Time, t = 15 s
We need to find the acceleration of the plane and distance it travel before takeoff.
[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{75-0}{15}\\\\a=5\ m/s^2[/tex]
Let the distance is d.
[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{(75)^2-(0)^2}{2\times 5}\\\\d=562.5\ m[/tex]
So, the acceleration is 5 m/s² and the distance is 562.5 m.
Consider two positive charges separated by a distance ((A 20)/100) meters. One charge has a value of (B 5) mC (milli-coulombs) and is located to the right of the other (C 5) mC charge. Assume the left charge is the origin and the other charge is located with a positive horizontal position. How large and in what direction is the electrostatic field at the mid-point, directly between the two charges
Answer:
E_total = 0
Explanation:
In this exercise we are asked for the electric field created by two charges at the midpoint between them, since the electric field is a vector magnitude it must be added as vectors. The equation that describes the electric field for a charge is
[tex]E = k \frac{q}{r^{2} }[/tex]
in this case the two charges are positive, therefore the field is salient, in the adjoint we can see a diagram of the system
E_total = E₁ -E₂
we calculate the electric field of charge 1 with q = + 5 10⁻³ C and a distance r = L / 2 = 100/2 = 50 m
E₁ = [tex]\frac{9 10^{9} \ 5 10^{-3} }{ 50^{2} }[/tex]
E₁ = 1.8 10⁴ N / C
the magnitude of the electric field of charge 2 is equal, but the sense is opposite.
Since the two charges have the same sign, the addition of vectors gives zero
E_total = 0
if the charges were of different signs, the fields would be added
E_total = 3.6 10⁴ N / A
A new prototype cup has been designed to keep liquids, such as hot coffee or cold annk, near their original temperature for long periods of time Which statement describes the function of the newly designed
cup
Answer:
hope this was good for u and I believe it would be solid
ANSWER FAST PLSSSSSS Use this diagram of the wave below to answer any questions that follow
Answer:
1. Letter A indicates the crest.
2. Letter E indicates the wavelength.
3. Letter C indicates the trough.
Explanation:
1. Determination of the the crest.
A crest is simply defined as a point on a wave where the displacement is maximum (i.e highest).
Considering the diagram given above, the point where the displacement is maximum is A. Therefore, A is the crest of the wave.
2. Determination of the wavelength.
The wavelength of a wave is simply defined as the distance between two successive crest or trough.
Obeserving the diagram above, we can see that E gives the distance between two successive crest. Therefore, E is the wavelength of the wave.
3. Determination of the trough.
A trough is simply defined as a point on a wave where the displacement is minimum (i.e lowest). Thus we can say that the trough is the opposite of the crest.
Considering the diagram given above, the point where the displacement is minimum is C. Therefore, C is the trough of the wave.
Select the correct answer.
Cereal plants gain chemical potential energy as they grow. Which form of energy is converted to create the chemical potential energy?
O A gravitational potential energy
OB.
kinetic energy
OC light energy
OD.
thermal energy
Answer:
c
Explanation:
A softball player slows to a stop while sliding
across the infield dirt into third base.
This situation can best be described as a transformation of
Kinetic energy into Chemical Energy
Kinetic energy into Dissipated energy (e.g., heat and sound)
Potential energy into Chemical energy
Chemical energy into Kinetic energy
Chemical energy into Dissipated energy (e.g., hot and sound)
Answer:
Chemical energy into Kinetic energy
Explanation:
. A falling rubber ball of mass 0.025 kg strikes the ground traveling straight down at 4.0 m/s. Find the magnitude of the impulse that the ground gives to the ball if
a) the ground is soft and the ball stops dead
b) the ground is hard and the ball bounces straight back at 2.0 m/s.
Given that,
Mass of the ball, m = 0.025 kg
Initial speed, u = 4 m/s
To find,
Impulse when (a) the ground is soft and the ball stops dead
(b) the ground is hard and the ball bounces straight back at 2.0 m/s.
Solution,
Impulse = change in momentum
J = m(v-u)
(a) u = 0 (as it stops)
J = 0.025(4-0)
J = 0.1 N-m
(b) v = 2 m/s
J = 0.025(4-2)
= 0.05 N-m
Therefore, this is the required solution.
In Requiem for a Dream, the DP uses a device that straps the camera to the actor's chest to achieve a very subjective shot. What is this apparatus called
Answer:
A snorricam
Explanation:
The apparatus used here is a snorricam. A snorricam can be described to be a camera device which is used during the making of films. The snorricam is rigged to the actor. It faces him or her directly in such a way that as they walk, they would not appear to make any movements but the things around them would. It is also called the bodymount camera.
Think of a hydropower dam. How is electrical energy produced from potential and kinetic energy?
1. Which is not an example of vaporization?
Bubbles form as water boils on the stove.
Water droplets form on a mirror during a shower.
Air gains moisture as it moves over the ocean.
Wet pavement dries after a rain shower.
"Wet pavement dries after a rain shower" is not an example of vaporization. The correct answer is D.
What is vaporization?
Vaporization is the process by which a liquid is converted into a gas or vapor. The two main types of vaporization are boiling and evaporation.
Here in the Question,
Option A: Bubbles form as water boils on the stove. This is an example of vaporization by boiling, which occurs when a liquid is heated to its boiling point and its vapor pressure becomes equal to the atmospheric pressure.
Option B: Water droplets form on a mirror during a shower. This is an example of vaporization by evaporation, which occurs when a liquid changes into a gas at temperatures below its boiling point. In this case, the water on the mirror evaporates due to the heat and humidity in the shower.
Option C: Air gains moisture as it moves over the ocean. This is also an example of vaporization by evaporation. The warm air over the ocean absorbs moisture from the water surface, causing the water to evaporate and form water vapor in the air.
Option D: Wet pavement dries after a rain shower. This is not an example of vaporization. The water on the pavement may evaporate due to the heat and dryness of the surrounding air, but this process does not involve a liquid changing into a gas or vapor. Rather, the water on the pavement may be absorbed by the ground, run off into nearby drainage systems, or be removed by physical means like squeegees.
Therefore, among the given options, option D is not an example of vaporization.
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Your science teacher needs to make more of a salt-water mixture. The
concentration of the mixture that is needed is 35 grams of salt in 1,000
milliliters of water. How many grams of salt will be needed to make 1,500
milliliters of the salt water?
Answer:
52.5 g of the salt
Explanation:
From the question given above, we were told that concentration of the mixture that is needed can be obtained as by dissolving 35 g of salt in 1000 mL of water.
Thus, we can obtain the mass of the salt needed to make 1500 mL of the salt water mixture as follow:
35 g of salt dissolves in 1000 mL of water.
Therefore, Xg of the salt will dissolve in 1500 mL of water i.e
Xg of salt = (35 × 1500)/1000
Xg of salt = 52.5 g
Thus, 52.5 g of the salt is needed to make 1500 mL of the salt water mixture.
You throw a ball into the air. Which two forces cause the ball to gradually stop moving upward and then fall back to Earth?
A.
Balanced forces
B.
Friction
C.
Normal force
D.
Gravitational force
will mark brainliest
Answer:
I'm pretty sure the answer is D
Explanation:
Honestly it's just a guess so let me know if it's right :3
Answer:
it should be A and B
Explanation:
because obviously gravity causes it to fall down and the second force acted upon it is Friction from the air and ball coming in contact with eachother. I hope this helps
Suppose you have an object tied to a rope and are rotating it over your head in uniform circular motion. What would have to do to the rope length in order to cut the centripetal force in half
Answer:
We must duplicate the length of the rope (R'=2R) to get
[tex]F'=\frac{1}{2}F[/tex]
Explanation:
The equation of the centripetal force is given by:
[tex]F_{c}=ma_{c}[/tex]
[tex]F_{c}=m\frac{v^{2}}{R}[/tex]
Where:
R is the length of the rope
m is the mass of the object
v is the speed of the object
If we want to reduce the centripetal force in half, we can duplicate the length of the rope (R'=2R), which means:
[tex]F'_{c}=m\frac{v^{2}}{R'}[/tex]
[tex]F'_{c}=m\frac{v^{2}}{2R}[/tex]
[tex]F'_{c}=\frac{1}{2}F_{c}[/tex]
I hope it helps you!
Today basketball is played with nine players on the court at a time.
True
False
Answer:
yes basketball is played with nine players
Which of the following is true about a field goal?
A shot from half court.
It is worth two points.
It is shot from behind the 3-point line.
It is a free shot given when a player is fouled.
Answer:
which sport are you referring to?
Explanation:
What is this question formula a=V²-U² /2S?
Answer:
sorry I don't really know about that question.
Explanation:
Can earthquakes occur in an area with no fault and no volcanoes?Why?
ill give brainliest to 1st that answers
Answer:
No
Explanation:
Earthquakes cannot occur in an area with no fault and no volcanoes.
An earthquake is the sudden movement of within the earth usually along a fault surface.
Earthquake releases a huge amount of energy that can be very destructive to the surrounding environment where the quake was triggered. Tectonic movement due to fault displacement is the leading cause of earthquakes. Also, faults can be reactivated by fluid dispersion along fault planes.Therefore, earthquakes are closely and tightly related to faults and volcanoes.
Which of the following are car safety features that rely on increasing the
time of a crash? *
seat belts
crumple zones
air bags
all of the above
If the balloon can barely lift an additional 3500 N of passengers, breakfast, and champagne when the outside air density is 1.23 kg/m3, what is the average density of the heated gases in the envelope
The complete question is :
A hot-air balloon has a volume of 2100 m3 . The balloon fabric (the envelope) weighs 860 N . The basket with gear and full propane tanks weighs 1300 N .
If the balloon can barely lift an additional 3400 N of passengers, breakfast, and champagne when the outside air density is 1.23kg/m3, what is the average density of the heated gases in the envelope?
Solution :
Given volume of the hot air balloon [tex]$=2100 \ m^3$[/tex]
The balloon fabric weights = 860 N
The weight of the basket with the gear and propane tank = 1300 N
Density of outside air [tex]$= 1.23 \ kg/m^3$[/tex]
∴ Total pay load = Weight of the air displaced - weight of gas inside the balloon
Total pay load = 860 + 1300 + 3400
= 5560 N
Mass = density x volume
Weight [tex]$= \text{mass} \times g$[/tex]
Weight = volume x density [tex]$\times \text{ acceleration due to gravity (g)}$[/tex]
Weight of the displaced air = 2100 x 1.23 x 9.8
= 25313 N
Weight of the gas inside the balloon = density [tex]$\times \text{ acceleration due to gravity (g)}$[/tex] x volume
= density x 9.8 x 2100
= density x 20580 N
Therefore substituting the values, we get
⇒ 25313 - (density x 20580) = 5560
⇒ density [tex]$=\frac{19753}{20580}$[/tex]
[tex]$= 0.96 \ kg/m^3$[/tex]
So the density of the heated gas [tex]$= 0.96 \ kg/m^3$[/tex]
____ is the perceived frequency of a sound wave.
Answer:
Pitch is the correct answer!
Explanation:
~Hope this helps! :)
PLEASE HELP The graph shows the amplitude of a passing wave over time in seconds (s). What is the approximate frequency of the wave shown?
A.6 Hz
B.0.3 Hz
C.0.7 Hz
D.3 Hz
Answer:
[tex]F = 0.3\ Hz[/tex]
Explanation:
Given
See attachment for the graph
Required
Determine the frequency
Frequency (F) is calculated as:
[tex]F = \frac{1}{T}[/tex]
Where
T = Time to complete a period
From the attachment, the wave complete a cycle or period in 3 seconds..
So:
[tex]F = \frac{1}{3s}[/tex]
[tex]F = 0.333\ Hz[/tex]
[tex]F = 0.3\ Hz[/tex] --- Approximated
Answer:
0.3Hz
Explanation:
I took the test :)
Paola conducts an investigation to determine how temperature affects plant growth. Each plant started at the same height, received the same amount of water and was planted in the same type of soil She
recorded her results every seven days for three weeks.
Pls help
Answer:
HE IS WON
Explanation:
JESUS
A train travels at 100 km/h heading east to reach a town in 4 hours. The train then reversed ad heads west at 50 km/h for 4 hours
Color is a result of the absorption and reflection of light. A shirt appears a color because it reflects that color of light. A shirt appears black when it absorbs all wavelengths of light.
Why does a shirt appear white outside on a sunny day?
O The light is transmitted through the shirt, so no color
wavelengths of light.
appears.
O The shirt absorbs the sunlight, so it appears white.
O All the light is reflected, so the shirt appears white.
The sunlight refracts when it hits the shirt, so the shirt
appears white.
Answer:
the light is reflected, because light is white when the spectrum is combined, and white reflects white. that's why wearing a white shirt outside feels cooler than wearing a black shirt, since it doesn't absorb light.
Answer:
All the light is reflected, so the shirt appears white.
Explanation:
A guitar player can change the frequency of a string by "bending" it-pushing it along a fret that is perpendicular to its length. This stretches the string, increasing its tension and its frequency. The B string on a guitar is 64 cm long and has a tension of 74 N. The guitarist pushes this string down against a fret located at the center of the string, which gives it a frequency of 494 Hz. He then bends the string, pushing with a force of 4.0 N so that it moves 8.0 mm along the fret.
* What is the new frequency?
Answer:
[tex]f'=504hz[/tex]
Explanation:
From the question we are told that
The B string on a guitar is 64 cm long
The B string tension tension of 74 N.
Frequency of 494 Hz
Pushed with a Force of 4.0 N
It moves 8.0 mm along the fret.
Generally the equation for frequency of ring under tension is mathematically given as
[tex]2Lf=\sqrt{x\frac{T}{\mu} }[/tex]
[tex]2*(64/100)*494=\sqrt{\frac{74}{m/0.64}[/tex]
[tex](632.32)^2={\frac{74}{m/0.64}[/tex]
[tex](632.32)^2=74*{\frac{0.64}{m}[/tex]
[tex](632.32)^2={\frac{47.36}{m}[/tex]
[tex]m=1.18450761*10^-^4[/tex]
Therefore finding the New frequency f'
[tex]f'=\frac{(\sqrt{\frac{74+11}{(\frac{1.18450761*10^-^4}{0.642})}})}{2*0.642}[/tex]
[tex]f'=\frac{(\sqrt{(\frac{74+11}{1})*(\frac{0.642}{1.18450761*10^-^4}})}{2*0.642}[/tex]
[tex]f'=\frac{(\sqrt{(\frac{85}{1})*(\frac{0.642}{1.18450761*10^-^4}})}{2*0.642}[/tex]
[tex]f'=\frac{(\sqrt{(\frac{54.57}{1.18450761*10^-^4}})}{2*0.642}[/tex]
[tex]f'=\frac{678.7471973}{2*0.642}[/tex]
[tex]f'=572.9111096hz[/tex]
A rock weighing 6 Newton’s is lifted 2 meters. How much work is done?
Answer:
12 Joules
Explanation:
I believe a Joule is a Newton meter, and work is represented in joules, so 6 N * 2m = 12 Nm (joules)
ITS ACTUALLY ASTRONOMY
What is the name for a star that has two shells of hydrogen and helium undergoing fusion?
A. asymptotic giant branch star
B.Supergiant
C. hypergiant
D. supernova
*please help thx*
Answer:
A. Asymptotic giant branch star
Explanation:
Hope this helped.
Answer:
asymptotic giant branch star
Explanation:
Plato/Edmentum
why iron-rims are heated before putting them on the wheels of Bullock-carts?
Answer:
Explanation:
The iron ring to be put on the rim of a cart wheel is always of slightly smaller diameter than that of the wheel. When the iron ring is heated to become red hot, it expands and slips on to the wheel easily. When it is cooled, it contracts and grips the wheel firmly.
Explanation:
Iron rims are made slightly smaller than the wheels. They are heated red hot before fixing them on the cart wheels to expand them so that they can be easily fixed on the wheels and water is poured on them to cool them. As the rims cool they contract and take the shape of the wheel and get firmly fixed on the wheels.
So iron-rims are heated before putting them on the wheels of Bullock-carts
Hope it will help :)
Where does the energy in an unburned match come from?
A matchstick has a lot of chemical energy stored in it. When the match is struck, it burns and the chemical energy in it produces heat energy and light energy.
A matchstick has a lot of substance energy set aside in it. Right when the match is struck, it consumes and the engineered energy in it produces heat energy and light energy.
What is the energy?Chemical energy is the energy that is released when organic compounds engage in a chemical reaction and change into other substances. Batteries, food, and gas are a few examples of chemical energy storage mediums.
The types of energy are as follows:
Electrical EnergyChemical EnergyMechanical EnergyThermal EnergyNuclear EnergyThe energy can not be made and it can not be vanished. But it can be transform from one form to another form.
A matchstick has a ton of substance energy put away in it. At the point when the match is struck, it consumes and the synthetic energy in it produces heat energy and light energy.
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