The velocity of the rock after 2s is 12.56 m/s.
The velocity of the rock at 25 m upwards is 14.68 m/s.
The velocity of the rock at 25 m downwards is -15.97 m/s.
The given parameters;
velocity of the rock, u = 20 m/sheight of the rock, h = 20t - 1.8t²The velocity of the rock after 2s is calculated as follows;
[tex]v = \frac{dh}{dt}= 20 -2(1.86)t \\\\v = 20 - 3.72t\\\\at \ t= 2 \ s \\\\v = 20 - 3.72(2) = 12.56 \ m/s[/tex]
The velocity of the rock when the height is 25 m:
h = 20t - 1.8t²
25 = 20t - 1.8t²
1.8t² - 20t + 25 = 0
solve for the time of motion "t" using quadratic formula
a = 1.8, b = -20, c = 25
[tex]t = \frac{-b \ \ +/- \ \ \sqrt{b^2 - 4ac} }{2a} \\\\t = \frac{-(-20) \ \ +/- \ \ \sqrt{(-20)^2 - 4(1.8\times 25)} }{2(1.8)}\\\\t = 9.67s, \ \ or \ 1.43 \ s[/tex]
The value of t that will give 25 m upwards using the motion model is 1.43 s;
h = 20(1.43) - 1.86(1.43)² = 25 m
The velocity of the rock at 25 m upwards (t = 1.43 s) is calculated as follows;
[tex]v = \frac{dh}{dt} = 20 -3.72t\\\\v = 20 - 3.72(1.43) \\\\v = 14.68 \ m/s[/tex]
The velocity of the rock at 25 m downwards (t = 9.67 s) is calculated as;
[tex]v = \frac{dh}{dt} = 20 - 3.72t\\\\v = 20 - 3.72(9.67)\\\\v = -15.97 \ m/s[/tex]
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25. Which of the following cannot be broken down into smaller parts through ordinary chemical means?
a. Nitrogen
b. Protein
C. Salt
d. Sugar
Answer:
the correct answer is sugar
A baseball is traveling with a velocity of 12 m/s at an angle of 45 above
horizontal. What is the velocity of the ball after two seconds?
Focus on the ball. Do you see you? Keep following it. Put all your energy into watching it and then unlock your third eye. With that you'll be able to determine your question.
Câu 2: Một xe có khối lượng 20 tấn, chuyển động chậm dần đều dưới tác dụng của một lực 8000 N, vận tốc ban đầu của xe là 20 m/s. Gia tốc của xe là bai nhiêu?.
Answer:
?
Explanation:
Answer:
Explanation:yy
Name the type of joint present in skull.
Answer:
Sutures are nonmoving joints that connect bones of the skull
Explanation:
These joints have serrated edges that lock together with fibers of connective tissue.
Answer:
Immovable fibrous joints are present in our skull
Explanation:
brainliest plz
Câu 20: Chọn câu sai:
A. Công là đại lượng vô hướng B. Công không có tính tương đối
C. Công phụ thuộc vào đường đi D. Công có giá trị đại số
Answer:
fr
Explanation:
The weather that characterizes an area is the O latitude of that area O barometric pressure of that area climate of that area O geography of that area
Answer:
climate of that area
Explanation:
hola buen día por favor alguien me puede ayudar por favor1. Dos cargas puntuales q1=+4μC y q2=+ 6μC están separadas por 10 cm. Una carga
puntual
q3=+2μC se coloca a medio camino entre q1 y q2. Encuentra la magnitud y la dirección de la
fuerza resultante sobre q3. Asuma que q1 está a la izquierda de q3 y q2 a la derecha de q3.
Revisa el ejemplo de la clase del tema 6. Además, recuerda que las fuerzas no siempre actúan
en la misma dirección.
2. Se coloca una carga puntual de 4 μC en un punto P (x = 0.2 m, y = 0.4 m). ¿Cuál es el campo
eléctrico E debido a esta carga en el origen del plano cartesiano? Hint: asume un plano
cartesiano y dibuja el campo eléctrico que se busca. Además, recuerda el teorema de
Pitágoras.
3. Una carga puntual q = 25μC está ubicada en el centro de una esfera de radio R = 25 cm, el
campo eléctrico generado a esta distancia debido a esa carga es E=3.6 x 10^6 N/C. Se quita de
la superficie una sección circular con radio r = 5 cm. Encuentre el flujo eléctrico que pasa por
esta sección. Hint: solo quieres saber el flujo eléctrico sobre el área de la superficie que se
aisló, por lo que es importante recordar cómo se obtiene el área de un círculo.
4. En cierta región al norte del planeta tierra, existe un campo eléctrico uniforme, la dirección
del campo eléctrico es hacía el centro del planeta y según se sabe, tiene un valor de 1000 N/C.
Encuentra el cambio de la energía potencia eléctrica de una partícula que tiene una carga de
-1.6 x10 -19 C. Considera que la partícula se suelta en un punto A y llega hasta un punto B que
está a 50 m del punto A.
5. Dos cargas q1 = −2 μC y q2 = + 2 μC se fijan en sus posiciones y se separan por una distancia d
= 10 cm. ¿Cuál es el potencial eléctrico en el origen debido a estas dos cargas?
Answer:
vfyugpuvfhvjvfhuvihfiurj
Explanation:
vfehgwfljhgiurnjfkfjhk
What is the main tenet of mechanical philosophy
Answer:362
Explanation:
i just want the points
Answer:
Some ancient philosophies held that the universe is reducible to completely mechanical principles—that is, the motion and collision of matter. This view was closely linked with materialism and reductionism, especially that of the atomists and to a large extent, stoic physics.
Explanation:
Hope this helps.
Am I correct? Plz answer ASAP! I will give brainilest:D (Science)
Answer:
I would agree with your selection.
Explanation:
A boy of mass 43.2 kg runs and jumps onto a stationary skateboard.The boy lands on the skateboard with a horizontal velocity of 4.10 m/s.The skateboard has a mass of 2.50 kg.
Using ideas about conservation of momentum, calculate the combined
velocity of the boy and skateboard just after the boy lands on it.
Answer:
= 3.87 m/s
Explanation:
Since momentum is conserved, momentum right before and after the boy jumps onto the skateboard should be the same.
Initial momentum = momentum of boy = 43.2 x 4.10 = 177 kg·m/s
Final momentum = momentum of boy and skateboard = (43.2 + 2.50) x v = 45.7v
177 = 45.7v
v = 177 / 45.7 = 3.87 m/s
(Hope this helps can I pls have brainlist (crown)☺️)
The combined velocity of the boy and the skateboard just after the boy lands on it will be equal to 3.87 m/s.
What is momentum?Momentum is the product of a particle's mass and velocity. Being a vector quantity, momentum possesses both direction and magnitude. According to Isaac Newton's second equation of motion, the force applied on a particle is equivalent to the temporal rate at which momentum changes.
According to Newton's second law, the product of the energy and the time interval is equal to the shift in momentum if a constant force acts on a molecule for a specified amount of time.
Momentum should be the same both before and after the boy gets onto the skateboard because it is preserved.
Initial momentum = momentum of boy
= 43.2 × 4.10 = 177 kg m/s
Final momentum = momentum of boy as well as skateboard
= (43.2 + 2.50) × v = 45.7 v
177 = 45.7 v
v = 177 / 45.7 = 3.87 m/s
Therefore, the combined velocity of boy and skateboard is 3.87 m/s.
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what causes a solid air fresher to lose mass and volume
Answer:
A solid air freshener loses mass and volume as a result of sublimation, where solid particles skip the liquid state and change directly from a solid to a gas. Sublimation requires that the particles in the solid state gain enough energy to immediately become a gas.
Explanation:
Hope this helps.
A ball is projected with an angle o from the top of a tower of height h with velocity vo. The ball strikes the ground after a certain time t, then show a vo sino 2gh 1 + 1 + vo-sin20 t/
Answer:
dvnuncxtumvd7ojf433f and tv36v54f vs Craig
Two hicers are 13 miles apart and walking toward each other. They meet in 2 hours. Find the rate of each hiker if one hiker walks 1.7 mph faster than the other.
Answer:
Explanation:
Let r be the rate of the slower walker in mph
[r + (r + 1.7)](2) = 13
(2r + 1.7)(2) = 13
4r + 3.4 = 13
4r = 9.6
r = 2.4 mph
r + 1.7 = 4.1 mph
A person is driving a car in a roundabout at 20 m/s so that its centripetal acceleration is 5 m/s2 . How much time it takes to complete 1 circle around the roundabout?
Answer:
Ac = v²/r
where, Ac is centripetal acceleration
v is velocity
r is radius
5 = (20)²/r
r = 400/5
r = 80m
from,
w = 2πf
where, w = angular velocity and f frequency
w = v/r
f = n/T
then,
v = 2πrn ,n = 1 to complete 1 cycle
T
T = 2πr/v
T = 2π*80/20
T = 25.14seconds.
The car would take 25.14s to complete 1 cycle of the roundabout.
i just need help plzzzz
Answer:
I think D it's the correct answer!! Let me know if i'm wrong
Explanation:
When people do a bungee jump theyare asked how much they weigh. Why?
Answer:
The elasticity of the bungee cord reduces the gravitational forces applied on the body during bungee jumping. For example, if a 100-pound individual jumps from a building and encounters 900 pounds of deceleration force, they will feel 9 "G's" of force.
hopefully this'll help
have a nice day!!! :D
You are observing a star that is 250 million light years away. From the starlight you are observing now, the appears to be 30 million years old and you determine that the star has a lifetime of 120 million years. How long will it be until Earth receives light from the supernova that occurs at the end of the life of the star
What ever games your playing it wont work you cant defeat me hahhahha oh I know :O but he can AHHHH :D D: NOOOO IMPOSSIBLE.
Thinking Mathematically: Explore the quantitative dependencies of the acceleration upon the speed and the radius of curvature. Then answer the following questions. a. For the same speed, the acceleration of the object varies _____________ (directly, inversely) with the radius of curvature. b. For the same radius of curvature, the acceleration of the object varies _____________ (directly, inversely) with the speed of the object. c. As the speed of an object is doubled, the acceleration is __________________ (one-fourth, one-half, two times, four times) the original value. d. As the speed of an object is tripled, the acceleration is __________________ (one-third, one-ninth, three times, nine times) the original value. e. As the radius of the circle is doubled, the acceleration is __________________ (one-fourth, one-half, two times, four times) the original value. f. As the radius of the circle is tripled, the acceleration is __________________ (one-third, one-ninth, three times, nine times) the original value.
The expression for the centripetal acceleration allows to find the results for the questions are:
A) The acceleration varies INVERSELY with the radius of curvature.
B) The acceleration varies DIRECTLY with the speed.
C) The acceleration becomes four times greater.
D) The acceleration becomes nine times greater.
E) The acceleration is reduced to half.
F) The acceleration is reduced to a third.
In circular motion there must be an acceleration towards the center of the circle, it is called cenripetal acceleration, in this case all the energy supplied to the system is used to change the direction of the speed even when its magnitude remains constant.
[tex]a_c = \frac{v^2}{r}[/tex]
Where [tex]a_c[/tex] the centripetal acceleration, v is the speed and r the radius of curvature of the circle.
Now we can answer the questions about centripetal acceleration.
A) For the same speed, the acceleration varies INVERSELY with the radius of curvature.
B) For the same radius of curvature the acceleration varies DIRECTLY with the speed.
C) The speed is doubled
v = 2 v₀
[tex]a_c = \frac{(2v_o)^2 }{r}[/tex]
[tex]a_c = 4 \ \frac{v_o^2 }{r}[/tex]
The acceleration becomes four times greater than the original value
D) The speed is tripled
v = 3 v₀
[tex]a_c = 9 \frac{ v_o^2}{r}[/tex]
Acceleration becomes nine times greater than the original
E) the radius of curvature is doubled
r = 2 r₀
[tex]a_c = \frac{v_o^2}{2 r_o }[/tex]
[tex]a_c = \frac{1}{2} a_o[/tex]
Acceleration is reduced to half the original value
F) The radius of curvature is tripled
r = 3 r₀
[tex]a_c = \frac{v_o^2 }{3 r_o} \\ \\a_c = \frac{1}{3} a_o[/tex]
The acceleration is reduced to a third of the initial one.
In conclusion using the expression for the centripetal acceleration we can find the answers for the questions are:
A) The acceleration varies INVERSELY with the radius of curvature.
B) The acceleration varies DIRECTLY with the speed.
C) The acceleration becomes four times greater.
D) The acceleration becomes nine times greater.
E) The acceleration is reduced to half.
F) The acceleration is reduced to a third.
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A water rocket uses an amount of water and pressurized air to send a plastic rocket several feet into the air. As the water and air rush out the tail end of the rocket, the rocket shoots into the air. Which statement explains the rocket's motion?
Answer:
D.
For every action there is an equal and opposite reaction.
Explanation:
im doing the same one lol
For every action there is an equal and opposite reaction explains the rocket's motion.
What is rocket?A rocket is indeed a vehicle that accelerates by employing jet propulsion rather than the surrounding air. A rocket engine generates thrust by reacting to high-speed exhaust. Since rocket engines run solely on fuel carried within the vehicle, a rocket may travel in space.
A water rocket uses an amount of water and pressurized air to send a plastic rocket several feet into the air. As the water and air rush out the tail end of the rocket, the rocket shoots into the air. For every action there is an equal and opposite reaction explains the rocket's motion.
Therefore, for every action there is an equal and opposite reaction explains the rocket's motion.
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Describe the shape of the earth besides round and tell me how it rotates
Answer:
The Earth is in hydrostatic equilibrium pretty much. Which is to say that if it were entirely liquid it would still be the same shape ignoring minor differences like mountain ranges that are in any case indistinguishable on the large scale.
A spinning liquid sphere will flatten out somewhat at the axis poles and expand somewhat in its equatorial region and that’s the way the Earth is.
Hope it wirks
Energy Transfer and Temperature Quick Check 1 of 41 of 4 Items Question Use the table to answer the question. Sample Observation 1 The drop of food coloring spreads slowly. 2 The drop of food coloring spreads very quickly. A student places a drop of food coloring into two water samples. Her observations are shown in the table. Which statement best explains the observations in the table? (1 point) The water molecules of sample 1 are moving faster. The water molecules of sample 1 are moving faster. The temperature of sample 2 is close to freezing. The temperature of sample 2 is close to freezing. The temperature of sample 2 is higher. The temperature of sample 2 is higher. The water molecules of sample 1 are transferring more kinetic energy. The water molecules of sample 1 are transferring more kinetic energy.
Answer: Measure the initial temperature of the water using the thermometer Poke through a food substance measuring 0.5 grams using the needle with the handle. Turn on fire on the burner. Set the food substance on the needle to fire on the burner. Once the food substance starts to burn, place it under the test tube so the water inside it can absorb heat.
Explanation:
Hope this helps!
A 3 kg drone starts at 5 meter above the ground and reached 25 meter above the
ground. Find the potential energy of the drone. Formula: PE=mghf-hi
The gas state of water
Answer:
The gas state of water is water vapour. It is formed by boiling liquid water or from the sublimation of ice (sublimation is the process of converting a solid to a liquid). Hope this helps!
A box is 30 cm wide, 40 cm long and 25 cm high. Calculate the volume of the box in cubic centimeter.
A) 3,000
B) 30,000
C) 15,000
D) 1,200
Answer:
The correct answer would be A: 3,000.
Explanation:
To find the volume of a box, you have to do l * w * h. You multiply 30, 40, and 25 which gives you an answer of 3,000 cubic centimeters.
A chemical system is considered to have reached dynamic equilibrium when:__________.
a. the frequency of collisions between the reactant molecules is equal to the frequency of collisions between the product molecules.
b. the rate of production of each of the product species is equal to the rate of consumption of each of the reactant species. c. the rate of production of each of the products is equal to the rate of their consumption by the reverse reaction.
d. the sum of the concentrations of each of the reactant species is equal to the sum of the concentrations of each of the product species.
e. the activation energy of the forward reaction is equal to the activation energy of the reverse reaction.
Answer:
D
Explanation:
Sum of the concentrations of each of reactant species is equal to the sum of the concentrations of each of the product species
I NEED A 100% ACCURATE ANSWER FOR THIS QUESTION ASAP NO LINKS !!!
What describes the pressure in a contained fluid?
1: unknown as long as the fluid is contained
2: the same throughout the fluid
3: higher in some places and lower in other places
Answer:
3) higher in some places nd lower In other places
Explanation:
The pressure in a fluid is given by the law
p = p0 + pgh
where
p0 is the atmospheric pressure
p is the fluid's density
g is the acceleration of gravity
h is the depth at which the pressure is calculated
As we see, the pressure depends on the value of h (depth): therefore, points which are located at more depth experience a larger pressure than points located near the fluid's surface.
Does bouncing or sticking produce more impulse?
Answer:
yes
Explanation:
Bouncing is a way to increase impulse. Because an object that bounces changes directions the force of impulse must be absorbed then generated by the target object. (Impulse is nearly doubled.)
Please Help!!! I have no idea :(
1. During an experiment in which you are investigating the acceleration changes due to force changes, what value must stay constant during these trials?
a. Force
b. Velocity
c. Acceleration
d. Mass
2. An animal is walking forward. There is an applied force from the animal of 25 N to the right, a frictional force of 18 N to the left, a force of gravity of 65 N down and the animal is being pushed up by the ground with 65 N. What best describes the motion of the animal?
a. The animal will move to the left due to an unbalanced force on the left
b. The animal will move to the right due to an unbalanced force on the right
c. The animal will move down due to an unbalanced force down
d. The animal will move up due to an unbalanced force upwards
3. Two rockets are being tested. Both rockets have the same mass. One rocket accelerates at a higher rate than another rocket. What could be true about the difference between the rockets?
a. One rocket has more fuel than the other
b. One rocket is more streamlined than the other
c. One rocket engine produces more force than the other
d. One rocket is more badly designed than the other
4. According to Newton's Third Law, if a sledgehammer hits a wall with a force of 1000 N, how much force does the wall hit the sledgehammer?
a. 0 N
b. 500 N
c. 1000 N
d. - 1000 N
Answer:
1. A. Force
2.
3. B. or C.
4. 1,000 N as well
Explanation:
1. Force is mass multiplied by acceleration. if force and mass stay constant, then according to that equation, the acceleration stays constant as well.
I couldn't figure out what number 2 is though. Sorry.
The value which must stay constant during these trial is:
A. ForceThe best description of the motion of the animal is:
B. The animal will move to the right due to an unbalanced force on the rightThe thing which could be true about the difference between the rockets is:
C. One rocket engine produces more force than the other
The amount of force which the wall hits the sledgehammer is:
C. 1000 N
Force is simply defined as the mass of a body which is multiplied by the acceleration and according to the laws of physics, if there is a constant in the mass and force, then the acceleration would also remain constant.
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Câu 1. Trường hợp nào dưới đây không phải là vật sáng?
A. Chiếc bút chì đặt trên bàn giữa ban ngày.
B. Chiếc bật lửa rơi giữa sân trường lúc trời nắng.
C. Mặt Trời.
Answer:
A
Explanation:
A. The pencil is on the table in broad daylight
Which of the following is NOT a way that a U-235 atom could fission?
Answer: A.
just did it
Explanation: