10. A 90 kg box is sliding across a surface at a constant velocity while experiencing a rightward applied
force of 40 N. Calculate the force of friction acting on the box.
A. -40N
B. +40N
C.-2.5 N
D. 0 N
If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
fr = -40 N
The wavelength of a water wave is 54 m. It has a frequency of 0.03 Hz. What is the velocity of the wave?
Answer:
1.62 m/s
Explanation:
Wavelength of the water wave= 54 m
The frequency is 0.03 Hz
Therefore the velocity can be calculated as follows
Velocity= frequency × wavelength
= 0.03 × 54
= 1.62 m/s
what type of friction present when you wrench on a car?
Answer:Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards.
Explanation:
Two masses 1.2kg and 1.8kg are connected to the ends of a rod of length 2m. Find the moment of inertia about the axes, 1)going through the mid point of the rod. 2)going through the centre of mass of two masses.
Answers: 1) 3 kg m²
2) 2.88 kg m²
Explanation: Question 1
I = m(r)²+ M(r)²
I = 1.2 kg × (1 m )² +1.8 kg ×(1 m )²
∴ I = 3 kg m²
Question 2
ACCORDING TO THE DIAGRAM DRAWN FOR QUESTION 2
we have to decide where the center of gravity (G) lies and obviously it should lie somewhere near to the greater mass. (which is 1.8 kg). Since we don't know the distance from center of gravity(G) to the mass (1.8 kg) we'll take it as 'x' and solve!!
moments around 'G'
F₁ d ₁ = F₂ d ₂
12 (2-X) = 18 (X)
24 -12 X =18 X
∴ X = 0.8 m
∴ ( 2 - x ) = 1.2 m
∴ Moment of inertia (I) going through the center of mass of two masses,
⇒ I = m (r)² +M (r)²
⇒ I = 1.2 × (1.2)² + 1.8 × (0.8)²
⇒ I = 1.2 × 1.44 + 1.8 × 0.64
⇒ I = 1.728 + 1.152
⇒ ∴ I = 2.88 kg m²
∴ THE QUESTION IS SOLVED !!!
Can you help with this question please
Answer:
First answer to the first question is Two people pulling a rope with the same force in a opposite direction. The other one would be 2.72N
Explanation:
Hope this helps you :)
if an atom was a scale, in which the nucleus is the size of an apple the electron.....
Answer:
the nucleus is the size of an apple, approximately 5 cm of radius e, the atom has a radius of R = 5 cm 104 = 50000 cm = 50 km
Explanation:
In the Rutherford experiments it was proved that the atomic nucleus has the volume 10-4 the volume of the atom.
If we make a scale design in which the nucleus is the size of an apple, approximately 5 cm of radius e, the atom has a radius of R = 5 cm 104 = 50000 cm = 50 km
This shows that almost the entire volume of the atom is empty.
What energy transformation takes place in the
solar panel?
Help please I would appreciate it
Answer:
i think the red runner travels greater distance ie.40 m
Explanation:
although ,the blue one travels 21 m but in the backward direction .so the correct ans is "the red runner travels 40 m"
What is net force?
A. The sum of all the forces acting on an object
B. The difference between the largest and smallest forces acting on
an object
C. The largest force acting on an object
D. The smallest force acting on an object
Answer:
A. The sum of all the forces acting on an object.
What is the lithosphere?
A. the outer layer of the Earth's crust
B. the inner core
C. the middle portion of the mantle
D. the outer core
Answer:
a. outer layer
Explanation:
lithosphere is right underneath the continental and ocean crust. it is approximately 100 km in deep and it is a brittle layer. It is broken into tectonic plates.
the inner core is located at the very center and its full of iron and nickel (so its not B)
on top of that is the outer core which is liquid (not D)
the middle portion of the mantle is the asthenosphere and mesosphere. they are right beneath the lithosphere. (not C)
so the best answer is A
what is a atomic nuclues
the maximum intensity levels of a trumpet, trombone, and a bass drum, each at a distance of 3m are 94 dB, 107dB, and 113dB respectively. What is the intensity level of the three different instruments when played simultaneously, again at 3m?
Answer:
β = 114 db
Explanation:
The intensity of sound in decibles is
β = 10 log [tex]\frac{I}{I_{o}}[/tex]
in most cases Io is the hearing threshold 1 10-12 W / cm²
let's calculate the intensity of each instrument
I / I₀ = 10 (β / 10)
I = I₀ 10 (β / 10)
trumpet
I1 = 1 10⁻¹² 10 (94/10)
I1 = 2.51 10⁻³ / cm²
Thrombus
I2 = 1 10⁻¹² 10 (107/10)
I2 = 5.01 10-2 W / cm²
low
I3 =1 1-12 (113/10) W/cm²
I3 = 1,995 10-1 W / cm²
when we place the three instruments together their sounds reinforce
I_total = I₁ + I₂ + I₃
I_ttoal = 2.51 10-3 + 5.01 10-2 + 1.995 10-1
I_total = 0.00251 + 0.0501 + 0.1995
I_total = 0.25211 W / cm²
let's bring this amount to the SI system
β = 10 log (0.25211 / 1 10⁻¹²)
β = 114 db
2.14x10^-7. What is the answer. Write in standered form
what would the net force be on the box in the problems shown below.( both force and direction). for all four diagrams. please explain answers.
1. A 3.8 kg scooter moves with a constant acceleration of 2.5 m/s”. Determine the net
applied force responsible for the acceleration.
Answer:
9.5 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3.8 × 2.5
We have the final answer as
9.5 NHope this helps you
The voltage between two points in a circuit is 3.6 V. If the resistance between
the points is 75 , what is the current, according to Ohm's law?
A. 76.6 A
B. 0.048 A
C. 20.8 A
D. 270 A
Correct answer is B!
Considering the Ohm's law, the correct answer is option B. the current is 0.048 A.
Definition of currentThe flow of electricity through an object, such as a wire, is known as current (I). Its unit of measure is amps (A). So the current is a measure of the speed at which the charge passes a given reference point in a specified direction.
Definition of voltageThe driving force (electrical pressure) behind the flow of a current is known as voltage and is measured in volts (V) (voltage can also be referred to as the potential difference or electromotive force). That is, voltage is a measure of the work required to move a charge from one point to another.
Definition of resistanceResistance (R) is the difficulty that a circuit opposes to the flow of a current and it is measured in ohms (Ω).
Ohm's lawOhm's law establishes the relationship between current, voltage, and resistance in an electrical circuit.
This law establishes that the intensity of the current that passes through a circuit is directly proportional to the voltage of the same and inversely proportional to the resistance that it presents.
Mathematically, Ohm's law is expressed as:
[tex]I=\frac{V}{R}[/tex]
Where I is the current measured in amps (A), V the voltage measured in volts (V); and R the resistance that is measured in ohms (Ω).
This caseIn this case, you know that the voltage between two points in a circuit is 3.6 V and the resistance between the points is 75 Ω.
Replacing in the Ohm's Law:
[tex]I=\frac{3.6 volts}{75 ohm}[/tex]
Solving:
I= 0.048 amps
Finally, the correct answer is option B. the current is 0.048 A.
Learn more about Ohm's law:
https://brainly.com/question/13076023
https://brainly.com/question/17286882?referrer=searchResults
https://brainly.com/question/2275770
Which is an example of a chemical change?
frying an egg
boiling water
melting butter
chopping onions
Answer:
Frying an Egg
Explanation:
When chemical bonds are broken or formed, new particles are created. Therefore, frying an egg is a chemical change because it results in the formation of new particles.
Frying an egg is an example of chemical change. Therefore, option (A) is correct.
What is the chemical change?A chemical change can be described as a change in which a chemical substance is converted into one or more new types of substances. Chemical changes occur through chemical reactions that result in substances with different properties.
Chemical changes are irreversible in nature and are also called permanent changes in which an entirely new substance is formed. We have three kinds of chemical change organic, biochemical and inorganic.
While frying an egg, the egg changes from a fluid to a strong one. The egg changes from a fluid protein into a strong mass. Actually, the strands of protein extend, permitting the protein to denature by breaking the chemical bonds and formation of a new product.
Therefore, Frying an egg is a chemical change while boiling water, melting butter, and chopping onions are physical changes.
Learn more about chemical change, here:
brainly.com/question/23693316
#SPJ6
You hit a hockey puck and it slides across the ice at nearly a constant speed.Is a force keeping it in motion?Explain.
Answer:
Explanation:
When the puck is sliding on the ice, there is no force being exerted on the puck to keep it moving forward. Instead, inertia keeps the puck moving forward. Friction between the puck and the ice gradually slows the puck down. You hit a hockey puck and it slides across the ice at nearly a constant speed
At constant speed and varying position of the hockey puck, implies a change in the velocity of the hockey puck and net force is acting on it to keep it in motion.
According to Newton's second law of motion, the force applied to a an object is directly proportional to the product of mass and acceleration of the object.
F = ma
Acceleration is the change in the velocity of an object per change in time of motion.
At constant velocity, the acceleration of an object is zero.When acceleration of an object is zero, the force on the object is zero.A constant speed (magnitude only) and change in the direction of the object, implies a change in velocity of the object.at changing velocity, the acceleration on an object is positive, and hence net force acts on the object.Thus, we can conclude that at constant speed and varying position of the hockey puck, implies a change in the velocity of the hockey puck and net force is acting on it to keep it in motion.
Learn more here: https://brainly.com/question/8722829
Of these electromagnetic waves, which has the A Over a unit distance, wave A has three crests and two troughs. The wave begins and ends at the rest position. B Over a unit distance, wave B has two crests and one trough. The wave begins at the rest position and ends at the top of a crest. C Over a unit distance, wave C has four crests and four troughs. The wave begins and ends at the rest position. longest wavelength?
Answer:
Wave B has the longest wavelength
Explanation:
The wavelength of a wave is the distance between two consecutive points that are in phase.
The wavelength of a wave is also defined as the distance between successive crests or troughs along the z-axis.
A crest is the point of maximum upward displacement whereas a trough is a point of maximum downward displacement.
Comparing the three waves A, B and C over a unit distance.
Wave A:
Wave A has three crests and two troughs. The wave begins and ends at the rest position. There are 2½ successive points in phase in wave A
Therefore, the wavelength = 1/2.5 = 0.4
Wave B:
Over a unit distance, wave B has two crests and one trough. The wave begins at the rest position and ends at the top of a crest. There are 1¼ successive points in phase in wave B
Therefore, the wavelength = 1/1¼ = 0.8
Wave C:
Over a unit distance, wave C has four crests and four troughs. The wave begins and ends at the rest position.
There are 4 successive points in phase in wave B
Therefore, the wavelength = 1/4 = 0.25
Therefore, wave B has longest wavelength
1. If a 4000 kg rocket reaches 7,000 m/s in 8 minutes after blastoff, what is its acceleration?
2. What force is being applied to the rocket?
3. What is the rocket's potential energy when it is 12 km off the ground?
(Hint - Change kilometers to meters)
4. If the rocket were to fall from the 12 km height, what would be its speed right before hitting the ground? (assume no air resistance)
+ answer all the questions plz
Answer:
I guess the Ans for second one is gravitational force
help please Derive an equation
Ta=1.44T1/2
Answer:
To derive an equation you must indicate the variable you want to solve for.Here we have tension of an object A and Tension 1.Two variables or unknown are given hence we cannot derive any other equations.
What is the turning effect of a force?
A force may cause an object to turn about a pivot. The turning effect of a force is called the moment of the force. Moments act about a pivot in a clockwise or anticlockwise direction.
Answer:
A force may cause an object to turn about a pivot. The turning effect of a force is called the moment of the force. Moments act about a pivot in a clockwise or anticlockwise direction.
Explanation:
list at least three examples of circular motion
Answer:
When an object moves with a constant speed in a circular path, then its motion is called as Circular motion.
Examples of Uniform Circular Motion :--
The moon moves in uniform circular motion around the earth.
A stoned tied to a thread and rotated in circular motion.
An athlete running on a circular track.
A satellite revolving around Earth.
100 points!! word bank!
⬇️Article⬇️
Have you ever cut an apple in half and looked at the layers inside? When you cut something in half, the resulting view is called a cross section. When you look at the cross section of an apple, you see several layers: the skin, the pulp, the core, and the seeds. Much like the apple, Earth is made up of layers, too. If you could look at a cross section of our planet, you would see the crust. the mantle, the outer core, and the inner core. If Earth were an apple, the crust would be the apple’s skin. The mantle would be the apple’s pulp, making up most of the inside. Earth also has a central core, similar to an apple’s core, though Earth’s core does not contain any seeds! Of course, scientists cannot cut the whole planet in half to see a cross section the way you can with an apple. How do you think scientists know about Earth’s internal layers?
Scientists divide Earth’s interior into distinct layers.
Scientists can distinguish different layers in Earth depending on the properties used to identify each layer. For example, scientists identify the crust, mantle, and core based on each layer’s basic chemical composition. In other words, the crust, mantle, and core are each made up of different chemical elements. The crust and mantle are composed primarily of the elements oxygen and silicon. These are known as silicates. Silicates of the mantle contain heavier elements. This makes them denser than those found in the crust. The core is composed of the densest materials, primarily iron and nickel. Earth’s layers can also be identified by using each layer’s physical state of matter. The crust and the uppermost part of the mantle, together, make up a layer called the lithosphere. The lithosphere is the cool, rigid, outermost layer of Earth. The lithosphere is in the solid
In a typical silicate molecule, a silicon atom is bonded to four oxygen atoms. The atoms form a crystal structure.
Scientists use models to represent the different layers of Earth’s interior.
When constructing a model of the layers of Earth, scientists need to consider the chemical composition, state of matter, and thickness of each layer. Just like the skin of an apple, Earth’s crust is very thin compared to the other layers. It is about 25–70 km thick beneath the continents. Under the oceans, the crust is only about 5–7 km thick; however, it is much denser. The mantle is much thicker than the crust is, taking up most of Earth’s volume. The mantle begins directly beneath Earth’s crust. It reaches all the way to the outer core, about 2,900 km below the planet’s surface. In other words, Earth is about 1% crust, 83% mantle, and 16% core.
The crust and uppermost mantle are solid. The rest of the mantle is solid with plasticity. The core is made of very dense iron and nickel. The outer core is liquid, because it is hot enough to melt the iron and nickel. The inner core is solid. Even though it is as hot as the outer core, there is so much pressure at the very center of Earth that the iron and nickel stay in a solid state.
Looking to the Future: Exploring Earth’s Interior
Despite what you may have read in stories or seen in movies, scientists have never journeyed to the center of Earth. In fact, scientists have never made it through Earth’s crust! However, this has not stopped them from trying. The crust at the bottom of the oceans is much thinner than the crust of the continents. Therefore, drilling through the oceanic crust is the best chance that scientists have to make it to the mantle.
Answer:
Except in the crust, the interior of the Earth cannot be studied by drilling holes to take samples. Instead, scientists map the interior by watching how seismic waves from earthquakes are bent, reflected, sped up, or delayed by the various layers.
Explanation:
A street bridge is 5.5m long if the linear expansion of steel is 0.00001 oc How much will it expand when temperatures is by 10oc? Give answer in Cm
Answer:
[tex]l_o=550.055\ cm[/tex]
Explanation:
Given that,
Length of a street bridge, l = 5.5 m
The coefficient of bridge, [tex]\alpha =0.00001 ^0 C[/tex]
We need to find how much will it expand when temperatures is by 10°C.
The change in length per unit original length is given by :
[tex]\dfrac{\Delta l}{l}=\alpha \Delta T\\\\\Delta l = l\alpha \Delta T\\\\=5.5\times 0.00001 \times 10\\\\\Delta l=0.00055\\\\(l_o-l)=0.00055\\\\l_o=0.00055+5.5\\\\=5.50055\ m\\\\l_o=550.055\ cm[/tex]
Hence, the length will expanded 550.055 cm.
When a ball is thrown upward, there is a loss of ____________ energy, but a gain in ___________ energy.
Answer:
Explanation:
Loss of potential energy but a gain in kinetic (becasue its falling)
Answer:
There is a loss of potential energy and a gain of kinectic
Explanation:
Look at this model of an atom. Where are the protons located and how many are there?
Answer:
protons are in the nucleus .
Explanation:
there are 6 protons
Use the following free body diagram to answer questions 8 and 9:
8. Calculate the net force acting on the cart.
A 0N
B. +60N
C -60N
D. +240 N
9. Calculate the cart's rate of acceleration
A +60 m/s
B. +8 m/s
C.-2m/s
D. +2 m/s
Answer:
8 is c and 9 is b it is shown though the practice as god lol
Question 8
The net force acting on the cart is:
F = 150 N - 90 N
F = 60 N
Question 9
By the Newtons second law:
F = ma
Solving for a:
a = F/m
a = 60 N / 30 kg
a = 2 m/s²
What is the water cycle ?
Answer:
The water cycle shows the continuous movement of water within the Earth and atmosphere. ... Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow. Water in different phases moves through the atmosphere (transportation).
Explanation:
It's the water cycle.
calculate the force necessary to keep a mass of 2 kg moving on a circular path of radius 0.2 m with a period of 0.5 second. what is the direction of this force