Which scientist first suggested that the sun was at the center of the solar system?
1 Galileo
2 Newton
3 Ptolemy
4 Copernicus
I rly need answers
Answer:
Nicolaus Copernicus
Explanation:
With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it.
#4 copernicus he was the first scientist
23. How does the microwave appliance work?
Answer: The microwaves are reflected within the metal interior of the oven where they are absorbed by food. Microwaves cause water molecules in food to vibrate, producing heat that cooks the food.
Explanation:
A 3.9 kg ball traveling towards a soccer player at a velocity of -3.5 m/s rebounds off the soccer player's foot at a velocity of +15.9 m/s. If the Force of contact between the ball and the player's foot was 25.9 N. For how long was the force applied?
Answer: 2.92 s
Explanation:
Given
Mass of ball is [tex]m=3.9\ kg[/tex]
The initial velocity of the ball is [tex]u=-3.5\ m/s[/tex]
Velocity after the rebound is [tex]v=15.9\ m/s[/tex]
Force during the contact is [tex]F=25.9\ N[/tex]
We know, change in momentum is Impulse
[tex]\Rightarrow F\cdot \Delta t=m(\Delta v)[/tex]
[tex]\Rightarrow 25.9\cdot \Delta t=3.9(15.9-(-3.5))\\\\\Rightarrow \Delta t=\dfrac{3.9\times 19.4}{25.9}=2.92\ s[/tex]
Thus, the force is applied for 2.92 s
Which of the following is not a vector
A) Acceleration
B) Length
C) Velocity
D) Force
Olivia is on a swing at the playground.
A girl is swinging on a swing set. At W she is about 45 degrees up and to the left. At X she is near the bottom of the swing just to the left. At Y she is near the bottom of the swing just to the right. At Z she is about 45 degrees up and to the right.
If the swing is moving from W to Z, at which point is her kinetic energy increasing and her potential energy decreasing? (based on a starting point of W)
W
X
Y
Z
Answer:b
Explanation:
b
Answer:
Its X
Explanation: took the test
Can someone help me with this, please? I have the answer but I need help with why the answer is that :(
A block of mass m is placed against the inner wall of a hollow cylinder of radius R that rotates about a vertical axis with a constant angular velocity, ω, as shown above. In order for friction to prevent the mass from sliding down the wall, the coefficient of static friction, μ, between the mass and the wall must satisfy which of the following inequalities? (Ans: μ is greater than or equal to g/(w^2r)
Answer:
See explanation below
Explanation:
Recall that the force of static friction is the product of the coefficient of static friction between surface and object, times the force applied perpendicular to the surface.
In our case, that perpendicular force has magnitude equal to the centripetal acceleration times the mass m of the block. The centripetal acceleration is defined as the quotient between the square of the tangential velocity divided by the radius at which the rotating mass is located (in our case R).
In order to estimate the tangential velocity given the angular velocity ω, we simply multiply it by R:
[tex]v_t=\omega\,R[/tex]
and therefore the force acting on the surface of the cylinder is:
[tex]F=m\,*\,a_c=m\,*\,\frac{v_t^2}{R} =m\,*\, \frac{\omega^2\,R^2}{R} =m\,*\,\omega^2\,*R[/tex]
The force of friction between the block and the inner wall of the hollow cylinder will then be: [tex]f=\mu\, *\,m\,*\omega^2\,*\,R[/tex]
In order for this force of static friction to be able to prevent the mass to slide down due to gravity, we need that the friction force is at least equal to the gravitational force. That is:
[tex]f\geq F_g\\f\geq m\,*\,g\\\mu\,*\,m\,*\,\omega^2\,*\,R\geq m\,*\,g\\\mu\geq \frac{g}{\omega^2\,*\,R}[/tex]
The force of static friction to prevent the mass to slide down due to gravity, the friction force is must be equal or greater than to the gravitational force.
The force of static friction is the product of the coefficient of static friction between surface,and force applied perpendicular to the surface.
The tangential velocity,
[tex]\bold {V_t = \omega R}[/tex]
So, the force acting on the surface of the cylinder,
[tex]\bold {F= m\times a_c}\\\\\bold {F= m \times \dfrac {V_t^2 }{R}}\\\\\bold {F = m \times \dfrac {\omega ^2R2}{R}}}\\\\\bold {F = m \times \omega ^2 \times R}[/tex]
The force of friction between the block and the inner wall of the hollow cylinder,
[tex]\bold {F_f = \mu \times m \times \omega ^2 \times R}[/tex]
Therefore, the force of static friction to prevent the mass to slide down due to gravity, the friction force is must be equal or grater than to the gravitational force.
To know more about static friction,
https://brainly.com/question/8790433
What are the two parts of the SCM
A. Sternal head, Lateral Head
B. Bilateral Head, Long Head
C. Sternal Head, Clavicular Head
helpp me please
Answer:
C. Sternal Head, Clavicular Head
find the kinetic energy of a 985 g bunny rabbit when running at 3.82 m/s. show work plz
Answer:
9.2m/s sir Thank me later
Answer:
Given
mass (m) =985 ☓ 0.001 , 0.985 kg
velocity (v) =3.82m/s
kinetic energy(k. e) =?
Form equation
[tex]k.e = \frac{1}{2} mv {}^{2} \\ = \frac{1}{2} \times 0.985 \times 3.82 {}^{2} \\ = 7.1868kj \\ kinetic \: enegy = 7.1868kj[/tex]
I hope this help
PLS HELP
Which of these is not needed to find the kinetic energy of an object?
a. Its shape
c. Its velocity
b. Its mass
d. All of the above
Answer:
Ik its mass and velocity but not sure if its also shape
Its shape of an object that is not needed to find the kinetic energy of an object.
What is kinetic energy?The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
To learn more about kinetic energy here
https://brainly.com/question/12669551
#SPJ2
Finish the sentence
Newton’s 3rd law states that for every force there is an _____________________
Forces always occur in ________
Whenever one object exerts a force on a second object, the second object always exerts a force __________ back on the first object.
Answer:
1. Equal and opposite reaction
2. Pairs
3. That is equal
Explanation:
I have tried my best but without knowing your curriculum or the possible answers it is difficult to know exactly what the answer would be... :(
Please mark as branliest ;)
- Hope this helped!
Which acids are found in acid precipitation?
understand friend
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can someone help me please?
Answer:
is this math of science
Explanation:
Which is greater, the force exerted by the Earth on the Sun, or the force exerted by the Sun on the Earth? Why?
Answer:
There is no great force, the force exerted by the Earth on the Sun, and the force exerted by the Sun on the Earth are equal
Explanation:
By definition...
Which graph represents a nonlinear relationship?
A straight line runs from 0 0 sharply upward.
A graphs shows 0 to 6 numbered on the horizontal axis and 0 to 40 on the vertical axis. The graph shows an upward trend.
A graphs shows 0 to 6 numbered on the horizontal axis and 0 to 40 on the vertical axis. The graph shows an downward trend.
A graphs shows 0 to 6 numbered on the horizontal axis and 0 to 40 on the vertical axis. The graph shows a curved line runs down from 28 0 to 0 2, then straight to 0 4 then curving upward to 6 28.
Answer:
The correct answer is D.
Explanation:
Im pritty sure;)
Answer:
D
Explanation:
edge
What’s the quotient in 80.64 ÷ 3.6
Answer:
30 30 30 yuhhhhhhhhhhhh
A 18 g ball is swung at a 1m long string.It revolves every 1 s,what is the magnitude of swing's tension?
Answer:
The magnitude of swing's tension is 0.71 N.
Explanation:
Given;
mass of the ball, m = 18 g = 0.018 kg
angular speed of the ball, ω = 1 rev/s
radius of the motion, r = 1 m
Angular speed in rad/s is calculated as follows;
[tex]\omega = \frac{2\pi \ rad}{rev} \times \frac{1 \ rev}{s} \\\\\omega = 2 \pi \ rad/s[/tex]
Linear speed of the ball, v;
v = ωr
v = 2π x 1
v = 2π m/s
The magnitude of swing's tension is calculated as the centripetal force keeping the ball in circular motion.
[tex]F_c =T = \frac{mv^2}{r} \\\\T= \frac{0.018 \ \times (2\pi )^2}{1} \\\\T = 0.71 \ N[/tex]
Therefore, the magnitude of swing's tension is 0.71 N.
Which is the first step in the fusion process?
Answer:
deuteron
Explanation:
Answer:
C. The Third Picture
Explanation:
EDGE 2021
A day-care center has a merry-go-round that consists of a uniform 240-kg circular wooden platform 4.00m in diameter. Four children run alongside the merry-go-round and push tangentially along the platform’s circumference until, starting from rest, the merry-go-round is spinning at a rate of 2.14 rev/minute. During the spin-up:
a) If each child exerts a sustained force of 26N, how far does each child run?
b) What is the angular acceleration of the merry-go-round?
SHOW ALL WORK AND STEPS PLEASE.
Answer:
a) The distance each child ran is approximately 0.232 m
b) The angular acceleration is 0.21[tex]\overline 6[/tex] rad/s²
Explanation:
The given parameters of the merry-go-round are;
The mass of the merry-go-round, m = 240-kg
The diameter of the merry-go-round, d = 4.00 m
The number of children pushing tangentially on the merry-go round = Four children
The spinning rate of the merry-go-round, n = 2.14 rev/minute
a) Given that the force exerted by each child = 26 N, we have;
The total force applied by the four children, F = 26 N × 4 = 104 N
The tangential acceleration, [tex]a_t[/tex] = F/m = 104 N/240-kg = 0.4[tex]\overline 3[/tex] m/s²
The angular acceleration, α = [tex]a_t[/tex]/r
Where, the radius of the merry-go-round, r = d/2
∴ r = 4.00 m/2 = 2.00 m
α = 0.4[tex]\overline 3[/tex] m/s²/(2.00 m) = 0.21[tex]\overline 6[/tex] rad/s²
We have;
ω² = ω₀² + 2·α·Δθ
The merry-go-round starts from rest, therefore; ω₀ = 0 rad/s
ω² = 2·α·Δθ
Δθ = ω²/(2·α)
n = 2.14 rev/minute
∴ ω = 2·π×2.14/60 rad/s ≈ 0.22410 rad/s
∴ Δθ = (0.22410 rad/s)²/(2 × 0.21[tex]\overline 6[/tex] rad/s²) ≈ 0.11589 rad
Therefore, the angle each child ran, θ = 0.11589 rad
The distance each child ran = r·θ
∴ The distance each child ran = 2.00 m × 0.11589 rad ≈ 0.232 m
b) From part 'a' above, the tangential acceleration, [tex]a_t[/tex] = 0.4[tex]\overline 3[/tex] m/s²
Angular acceleration, α = [tex]a_t[/tex]/r
∴ α = 0.4[tex]\overline 3[/tex] m/s²/(2.00 m) = 0.21[tex]\overline 6[/tex] rad/s²
The angular acceleration = 0.21[tex]\overline 6[/tex] rad/s²
write Newton's third low of motion and verify it with an experiment
Answer:
to something in action there is always a equal and opposite reaction. Like if you bounce a bounce ball on the ground, it will bounce back.
Explanation:
Give an example of two metals and non-metals that don't have the usual properties. Why are they so unusual.
Answer:
Metals is defined as the solid material which shows lustrous appearance and is a good conductor of electricity while non-metal are defined as the material which are not in solid form, have no luster and are bad conductor of electricity.
Two metals which are so unusual are mercury and sodium because metals are generally solid bur mercury is present in liquid form and metals are hard but sodium is so soft.
Two non-metals which are so unusual are diamond and iodine because diamond is opposite to the property of non-metals that is hard and iodine shows lustrous appearance whereas non-metals are non- lustrous.
Hence, Two example of metals are mercury and sodium and two example of non-metals are diamond and iodine.
Which state helps produce light in fluorescent lightbulbs?
A.
Solid
B.
Plasma
C.
Gas
D.
Liquid
If each contour line represents 50 meters, what is a reasonable height of the mountain peak in the topographic map? Record your answer and fill in the bubbles on your answer document. Be sure to use the correct
Answer:
Explanation:
Answer: None of the above I got it right on my test
Which would be a good use for an organic substance? Check all that apply.
electrical conductors
waterproof coatings
fuels such as gasoline
microchips
plastic storage containers
Answer:
B,C,E
Explanation:
Observa a tu alrededor y escribe el nombre de diez objetos que se encuentren en movimiento, Luego escribe el de otros diez que pienses que se encuentran en reposo. ¿Qué criterio tuviste en cuenta para considerar que están en reposo?
Answer:
Objetos que se encuentran en movimiento:
1) Un automóvil pasando por la calle.
2) Una crustácea que se acerca a mi casa.
3) Un avión volando en el cielo.
4) Un repartidor de comida desplazándose en una bicicleta.
5) Las aspas del ventilador en rotación.
6) Una hojarasca afuera de la casa.
7) La puerta de mi habitación abrirse.
8) Un mosquito entrando por la ventana.
9) Un metrónomo en movimiento.
10) Las hojas de mi cuaderno siendo agitadas por la brisa impulsada por el ventilador.
Objetos que se encuentran en reposo:
1) El semáforo de la esquina.
2) El automóvil de mi madre.
3) Las sillas del comedor.
4) Un jarrón de porcelana.
5) La nevera de la cocina.
6) La mesa de noche de mi habitación.
7) El automóvil de policía en la calle.
8) La impresora de memes.
9) El estante de libros.
10) El cesto de galletas.
Un objeto está en reposo si y solo si la posición de todos sus puntos no ha cambiado con respecto a la posición inicial en el tiempo. Los cambios de posición se manifiestan mediante tres formas:
(i) Traslación.
(ii) Rotación.
(iii) Deformación.
Explanation:
Objetos que se encuentran en movimiento:
1) Un automóvil pasando por la calle.
2) Una crustácea que se acerca a mi casa.
3) Un avión volando en el cielo.
4) Un repartidor de comida desplazándose en una bicicleta.
5) Las aspas del ventilador en rotación.
6) Una hojarasca afuera de la casa.
7) La puerta de mi habitación abrirse.
8) Un mosquito entrando por la ventana.
9) Un metrónomo en movimiento.
10) Las hojas de mi cuaderno siendo agitadas por la brisa impulsada por el ventilador.
Objetos que se encuentran en reposo:
1) El semáforo de la esquina.
2) El automóvil de mi madre.
3) Las sillas del comedor.
4) Un jarrón de porcelana.
5) La nevera de la cocina.
6) La mesa de noche de mi habitación.
7) El automóvil de policía en la calle.
8) La impresora de memes.
9) El estante de libros.
10) El cesto de galletas.
Un objeto está en reposo si y solo si la posición de todos sus puntos no ha cambiado con respecto a la posición inicial en el tiempo. Los cambios de posición se manifiestan mediante tres formas:
(i) Traslación.
(ii) Rotación.
(iii) Deformación.
Hydrogeneous Sediment include_____.
A) granite
B) evaporative salts
C) igneous rocks
D) metamorphic rocks
How many different simple machines on a bike? If you can please name the class of lever,pulley etc.
Answer:
there should be 4 2 levers and 2 wheels
Explanation:
Why does an ice cube melt in your hand? Question 3 options: The ice remains in a solid state even though heat is applied The temperature of the ice is greater than the temperature of your hand Sound energy creates vibrations which make the ice melt Heat is transferred from your hand to the ice making it melt
Answer:
3rd choice
Explanation:
heat is transfered causing it to melt
Answer:
C
Explanation:
A mover pushes a piano 15 meters across a stage by applying a force of 325 N. How much work does the mover do? *
Work = (force) x (distance)
Work = (325 N) x (15 m)
Work = 4,875 Joules
If an object can make 10 revolutions in two minutes, what’s it’s period?
Answer:
the answer is 12 second easy
Paul turns up the volume on his TV. The TV sends an electrical signal to the speakers. The signal changes the sound's
Answer:
increases its amplitude.
Explanation: