Answer:
10cm
Explanation:
25/20=x/8
cross multiply;
200=20x
x=10
A child is stationary on a swing.(a)The child is given a push by his brother to start him swinging.His brother applies a steady force of 84 N over a distance of 0.25 m.(i) Calculate the work done by this force.(2)..............................................................................................................................................(ii) State how much energy is transferred by this force.(1)..............................................................................................................................................(iii) After several more pushes, the child has a kinetic energy of 71 J.The mass of the child is 27 kg.Show that the velocity of the child at this point is about 2.3 m/s.(2)(iv) Which one of these quantities changes in both size and direction while he is swinging?Put a cross ( ) in the box next to your answer.(1)Ahis gravitational potential energyBhis momentumCthe force of gravity acting on himDhis kinetic energy
Answer:
Work done = Fs
Explanation:
(i) W = Fxs
= 84N x0.25m
= 21 Joules
(ii) Ek = 1/2mv^2
71 = 1/2×27×v^2
71×2/27 = v^2
v = 23m/s
The work done by this force is 21 Joule.
Energy transferred by the force is 21 Joule.
The boy's momentum changes periodically, that is, in both size and direction.
What is force?An external force is an agent that has the ability to change the resting or moving condition of a body. It has a direction and a magnitude. So, it is a vector quantity. Newton is the SI unit of force (N).
(i) Given parameter:
Steady force applied by his brother, F = 84 N.
Displacement, d = 0.25 m.
The work done by this force, W = F.d = 84×0.25 = 21 Joule.
(ii) Amount of work done is transferred by this force as an energy. So, amount of energy transferred by the force is 21 Joule.
(iii) Given parameter:
Mass of the child, m= 27 kg.
Kinetic energy, E = 71 J.
Let, velocity of the child = v, then kinetic energy is,
E = 1/2 × mv²
⇒ v = √(2E/m)
= √(2×71/27)
= 2.3 m/s.
Hence, the velocity of the boy is 2.3 m/s. (proved).
(iv) During swing, his velocity changes periodically. That's why, his momentum changes periodically, that is, in both size and direction.
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negatively charged particles of radiation emitted from the decay of radioactive substances are known as
Answer: beta particles
Explanation:
that's the answer
A man on the moon with a mass of 90 kilograms weighs 146 newtons. The radius of the moon is 1.74 x 10^6
meters. Find the mass of the moon
equation- F= G m1 m2/ d^2
Answer:
7.36 × 10^22 kg
Explanation:
Answer:
D
Explanation:
why are some small jovian planet moons geologically active?
Answer:
tidal heating and/or their composition
Explanation:
The kinetic energy of an object can sometimes be greater than a potential energy a originally possessed, true or false?
Answer:
true
Explanation:
Energy stored in the nuclei of atoms can be used to generate electricity. ... Most of the energy of food is converted to heat.
Do you think humans will ever walk on the sun?
[tex] \: \: \: \: \: [/tex]
yesbecause sun have a super nova and if someone get it there that person definitely get burnhope it helps
[tex] \: \: \: \: \: [/tex]
a box takes 350 N to start moving the coefficient of static friction is 0.35. what is the weight of the box?
Answer:
101.937 kg
Explanation:
The force needed to get the box moving must just cancel the static friction force:
F = µsmg = 0.35•m•9.81 = 350 ---> m = 350 / (0.35•9.81) = 101.937 kg
Again, with units shown, and using 1 N = 1 kg•m/s2:
0.35•m•9.81(m/s2) = 350 N
solving for m:
m = 350 N / (0.35•9.81 m/s2) = (350 kg•m/s2) / (3.434 m/s2 ) = 101.937 kg
______________________
(Hope this helps can I pls have brainlist (crown)☺️
a trip from Austin to Dallas takes about 3 hours going 65 mi/hr north is this speed, velocity, or acceleration?
Answer:volocity
Explanation:
what noncontact forces act on an object that are balanced
Answer:
I can give you a list of noncontact forces off of my head, if that is what you need.
Explanation:
First, gravity. It acts everywhere and pulls down every object that is in the air towards the ground, unless they have an equal and opposite force that counters it.
Second, wind. I don't think this will count because wind is a physical thing, but it can be used in the same way as we did with gravity. If the force counteracting it is larger, equal, and opposite of the force it is countering, then it will move forward, through the wind.
a child has the kinetic energy of 71 j the mass of the child is 27kg show that the velocity of the child at this point is 2.3m/s
Explanation:
kinetic energy of child = 1/2 m v^2
71 j. = 1/2×27kg ×v^2
71×2/27= v^2
142/27 = v^2
5.3. =v^2
v= √5.3
v= 2.3 m/s
A ball is falling toward the ground. Which of the following statements are false? (a) The force that the ball exerts on Earth is equal in magnitude to the force that Earth exerts on the ball. (b) The ball undergoes the same acceleration as Earth. (c) The magnitude of the force the Earth exerts on the ball is greater than the mag- nitude of the force the ball exerts on the Earth.
Hi there!
(A) The force that the ball exerts on Earth is equal in magnitude to the force that Earth exerts on the ball.
Gravitational force is an example of an action-reaction pair:
[tex]F_{1,2} = -F_{2,1}[/tex]
Gravitational force is given by the equation:
[tex]F_g = \frac{Gm_1m_2}{r^2}[/tex]
Plugging in the masses of the Earth and ball, gravitational constant, and radius will result in the SAME GRAVITATIONAL FORCE exerted by both objects on each other.
what is rotational dynamics
Rotational dynamics is the study of forces and motions about an axis of rotation.
Explanation:Formulas such as Kinematic Equations and Newton's laws can be expressed in rotating coordinate frames such as: Newton's 2nd Law Fnet=m x a translates into Torque = I x α Where I is Moment of Inertia (the rotational analogous term to mass)
Answer:
Rotational dynamics is the study of forces and motions about an axis of rotation.
Explanation:
Formulas such as Kinematic Equations and Newton's laws can be expressed in rotating coordinate frames such as:
Newton's 2nd Law Fnet=m x a translates into Torque =I x α Where I is Moment of Inertia (the rotational analogous term to mass)
and α is angular acceleration.
A person who sits on the right-hand seat of the car that is making a left turn slides over to the right. What is the possible reason for this?
Answer:
zsjgbjidasngwhugbhwuabvhuvbwhuebewghvwev
Explanation:
11111111111111111111111111111111111111111111111111111
HELP PLZZZZZZ AHHHHH
Answer: I think it's larger
Explanation: man im just trying to help you
The acceleration of an object is inversely proportional to its mass, so if you decrease its mass while keeping the net force the same, the acceleration will increase.
true or false
Answer:
True
Explanation:
Since acceleration is inversely proportional to mass, decreasing mass will make the object lighter, and thus easier to speed up. So acceleration increases as mass decreases and vice versa
Answer: TRUE Explanation:Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
Determine the work done by the force Fx=(6x-4)N as the object moves from x1=0 to x2=3 m.
Answer:
15J
Explanation:
Let's assume force and motion have the same direction, so the dot product between the two reduces to the product of magnitudes.
If you studied calculus: [tex]w= \int \limits^3_0 6x-4dx[/tex], by definition. Some "easy" math, that's [tex](3x^2-4x)\limits^3_0=27-12 - 0 = 15 J[/tex]
Else. we have to take the long way. if the force was constant, and you plotted magnitude of the force vs position in a graph, you would get an horizontal line, and your work would be the area between the line and the x axis. And there is no reason why it shouldn't be the same for a variable force - if you think about it, it's the same way they justify the position formula for an accelerated motion. Let's graph it and start debating - sorry for my paint skills. We can easily say that in the green triangle the force is opposing the motion, so its work is negative, while in the blue area force and displacement go in the same direction, thus work is positive. Now it's just to calculate the area of two triangles
For the green one, it's a right triangle with side lengths 4 and 2/3, whose area is [tex]\frac12(4)(\frac23) = \frac43[/tex].
For the blue triangle, it's again a right triangle with side lengths 14 and 3-2/3= 7/3, whose area is [tex]\frac12(14)(\frac73) = \frac{49}3[/tex]
Our total work is the difference between the two, or [tex]w= \frac{49}3-\frac43 = \frac{45}3 = 15[/tex]
plzz explain how it is 66 m
i know that distance =speed × time so how it is 66 m not a
0.4 and if there us another rule plz explain like if u day that 1/2 ×speed ×time plz explain why u used 1/2 or when do I use the 1/2 rule
Hi there!
For someone to hear an echo, the sound must echo and bounce back to the person.
Thus, the sound travels TWICE the distance from the person to the wall (to the wall and back).
We know that:
d = st (distance = speed × time)
Let L = distance from person to wall
Thus:
2L = st
2L = 330 × 0.40
2L = 132
L = 66 m
Describe the forces that make a bicycle move.
Answer:
this is an example of Newton's Second Law, acceleration happens when a force acts on a mass.
the force that makes the bicycle move is your foot pushing against the pedal
Which one of the following is not a vector quantity? a) Displacement b ) density c) force d) vecocity
Answer:
density
Explanation:
density is a scalar quantity having only magnitude and no info about derection
As the temperature of an air mass increases, its atmospheric pressure______. Group of answer choices
Answer:
its atmospheric pressure decreases
When the temperature of an air mass increases, its atmospheric pressure drops
ok done. Thank to me :>
a device that converts mechanical energy into electricity is a
Answer:
An electric generator is a device that converts a form of energy into electricity.
Explanation:
What are Newtons Laws famous for
Answer:
Why are Newton's laws of motion important? Newton's laws of motion are important because they are the foundation of classical mechanics, one of the main branches of physics. Mechanics is the study of how objects move or do not move when forces act upon them.
Which factor is not a type of spectra?
A.
emission
B.
absorption
C.
continuous
D.
discontinuous
A swimming pool has dimension of 30m×10m×3m. When it is filled with water , what is the thrust on the bottom and sides
Answer:
3,900m³
Explanation:
If two stars are in a binary system with a combined mass of 5.5 solar masses and an orbital period of 12 years, what is the average distance between the two stars
The average distance between the two stars is 792 light years
Let the mass of the first star be [tex]m_1[/tex]
Let the mass of the second star be [tex]m_2[/tex]
The combined mass of the two stars, [tex]m_1+m_2=5.5[/tex] solar masses
The orbital period of the stars, P = 12 years
Average distance between the two stars, D = ?
The average distance between the two stars can be calculated using Kepler's equation
[tex]D=(m_1+m_2)P^2[/tex]
Substitute [tex]m_1+m_2=5.5[/tex] and P = 12 into the formula [tex]D=(m_1+m_2)P^2[/tex]
[tex]D=5.5(12^2)[/tex]
D = 5.5(144)
D = 792 light years
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You are walking back toward the back of a bus that is moving forward with a constant velocity. Describe your motion relative to the bus and relative to a point on the ground.
Answer: Relative to the bus, you are stationary. Relative to a point on the ground, you are walking forward with velocity equal to the velocity of the bus.
As a person walks toward the back of a bus, they are walking towards a stationary object according to their own perspective. However, from an outside perspective, the bus is moving forward with a constant velocity and so relative to that point in motion, you are actually walking backwards with respect to it. This difference in motion means you would not be able have the same experience as the person on the bus when getting off because when you get off you would stop while they continue going forward. The last sentence could be considered a footnote because it only applies if this was an actual situation rather than just an analogy question in a physics test.
Relative to the bus, you move at walking speed. The motion relative to the ground is in the direction same as the bus and equal to the difference between the speed of the bus and walking speed.
What is relative motion?When an object has a certain velocity, then this velocity is w.r.t. some frame that is called the reference frame. When we measure the velocity of an object, the ground or the earth is taken as the reference frame.
The motion of an object observed by the observer depends on the frame of the observer and this type of motion is known as relative motion.
For example, if you are traveling in a train and the train is moving at a speed of 80 km/hr, then your speed according to another passenger sitting on the same train is equal to zero.
Similarly, if you are walking toward the back of a bus, then your motion relative to the bus is walking speed. Relative to the ground, it is the difference between the speed of the bus and walking speed.
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....................................
Answer:
yeah
Explanation:
Image credit: The Hubble Heritage Team (AURASTSCI/NASA)
To which category does galaxy #2 belong? Why does it belong in this category?
WRITER
Can i ask u a question
how to do the next ques for moreBrainliest me please
the thermodynamic processes that occur in nature ____________.
Answer:
The thermodynamic processes that occur in nature convert thermal energy into mechanical energy.
The thermodynamic processes that occur in nature are according to the law of thermodynamics.
The thermodynamics processes seen in nature are guided by the law of thermodynamics. The role of energy and heat transmission in physical systems is guided by these laws.
The laws are:
(1) Energy cannot be created nor destroyed in a system, according to the first law of thermodynamics, Also, referred to as the law of energy conservation. Only from one form to another, the energy can be transmitted or altered. Energy is conserved through natural processes, keeping the overall amount constant.
(2) Second law of thermodynamics: states that the overall entropy of an isolated system tends to increase over time in any natural process. This suggests that processes progress towards a state of increasing disorder.
Hence, the thermodynamic processes are guided by the law of thermodynamics.
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pls help me do these physic questions
Answer:
1 since it is meatl and sharp
2 since it is sharp and iron