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.

Answers

Answer 1

Answer:

A

Explanation:

A. The pencil is on the table in broad daylight


Related Questions

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

Answers

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. Force

The best description of the motion of the animal is:

B. The animal will move to the right due to an unbalanced force on the right  

The 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.

Read more here:

https://brainly.com/question/24557735

Find the angle between two equal forces (p) when their resultant is equal to (p)

Answers

Answer:

60°

Explanation:

It will be equilateral triangle, you can prove with the cosine theorem.

1)P^2=P^2+P^2 - 2×P×P× cos A

2) cos A= P^2 / 2× P^2 = 1/2

cos A = 1/2

A = 60°

If you wrote this question right,it will be solved like this :)

Toe toe toe toe toe toe

Describe the shape of the earth besides round and tell me how it rotates​

Answers

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

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?

Answers

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.

PLZ HURRY ANSWER THIS PLZ
Which statement best describes how Greensburg recovered from the tornado? O A. It doubled its population O B. It secured itself against future tornadoes. C. It became an eco-tourism destination © D. It built a new school and hospital.​

Answers

Answer:

C: it became an eco-tourism destination

Explanation:

Answer: Its C

Explanation:

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.

Answers

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 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

Answers

Recall that work is the amount of energy transferred to an object when it experiences a displacement and is acted upon by an external force. It is given a symbol of W and is measured in joules (J).

W=\vec{F}\cdot \Delta \vec{d}

We can use this formula to determine the work done by very specific forces, generating specific types of energy. We will examine three types of energy in this activity: gravitational potential, kinetic, and thermal. Before we start deriving equations for gravitational potential energy and kinetic energy, we should note that since work is the transfer and/or transformation of energy, we can also write its symbol as \Delta E.

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?

Answers

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.

To learn more about rocket, here:

https://brainly.com/question/29070000

#SPJ2

() The two forces F_{1} and F_{2} shown in Fig. 4- 39a and b (looking down) act on a 27.0-kg object on a frictionless tabletop . If F_{1} = 10.2N and F_{2} = 16.0N find the net force on the object and its acceleration for each situation , (a) and (b) .

Answers

It looks like 4.78 inches + 56x

How does the mass of the bob affect the number of swings of a pendulum?

Answers

Mass does not affect the pendulum's swing. The longer the length of string, the farther the pendulum falls; and therefore, the longer the period, or back and forth swing of the pendulum. The greater the amplitude, or angle, the farther the pendulum falls; and therefore, the longer the period

A 0.750 kg hammer is moving horizontally at 7.00 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board. (a) Calculate the duration of the impact in seconds. (Enter a number.) s (b) What was the average force in newtons exerted downward on the nail

Answers

Answer:nh

0.750 kg hammer is moving horizontally at 7.00 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board.

Someone help please i need to finish this

Answers

Answer:

4th answer

Explanation:

The gradient of a distance-time graph gives the speed.

gradient = distance / time = speed

Here, the gradient is a constant till 30s. So it has travelled at a constant speed. It means it had not accelarated till 30s. and has stopped moving at 30s.

if you double the force an object what will hapen to the accelration

Answers

Explanation:

the acceleration will double because force is directly proportional to the acceleration

What is the main tenet of mechanical philosophy

Answers

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.

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.

Answers

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 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?

Answers

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.

Name the type of joint present in skull.​

Answers

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

Answers

Answer:

fr

Explanation:

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

Answers

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.

Which of the following is NOT a way that a U-235 atom could fission?

Answers

Answer: A.

just did it

Explanation:

Does bouncing or sticking produce more impulse?

Answers

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.)

1. A small package is dropped from the Golden Gate Bridge. What is the velocity of the package
after it has fallen for 3.0 3?

Answers

The velocity of the package  after it has fallen for 3.0 s is 29.4 m/s

From the question,

A small package is dropped from the Golden Gate Bridge.

This means the initial velocity of the package is 0 m/s.

We are to calculate the velocity of the package  after it has fallen for 3.0 s.

From one of the equations of kinematics for objects falling freely,

We have that,

v = u + gt

Where

v is the final velocity

u is the initial velocity

g is the acceleration due to gravity

and t is time

To calculate the velocity of the package  after it has fallen for 3.0 s

That means, we will determine the value of v, at time t = 3.0 s

The parameters are

u = 0 m/s

g = 9.8 m/s²

t = 3.0 s

Putting these values into the equation

v = u + gt

We get

v = 0 + (9.8×3.0)

v = 0 + 29.4

v = 29.4 m/s

Hence, the velocity of the package  after it has fallen for 3.0 s is 29.4 m/s

Learn more here: https://brainly.com/question/13327816

what causes a solid air fresher to lose mass and volume

Answers

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.

Am I correct? Plz answer ASAP! I will give brainilest:D (Science)

Answers

Answer:

I would agree with your selection.

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?

Answers

Answer:

vfyugpuvfhvjvfhuvihfiurj

Explanation:

vfehgwfljhgiurnjfkfjhk

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/​

Answers

Answer:

dvnuncxtumvd7ojf433f and tv36v54f vs Craig

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?.

Answers

Answer:

?

Explanation:

Answer:

Explanation:yy

When people do a bungee jump theyare asked how much they weigh. Why?​

Answers

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

Which of the following is correct about the time period of a pendulum, whose length (length of thread) is 2 m and mass of whose bob (metallic ball) is 2 kg, when it is set in motion?

Answers

Answer:

P = 2 * pi * (L / g)^1/2        period of simple pendulum

P = 6.28 * (2 / 9.8)^1/2 = 2.84 sec

The gas state of water

Answers

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!

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