Answer:
1) v = 2.5 m / s, 2) v = -0.5 m / s
Explanation:
For this exercise we will use the kinematics relations
1) velocity is defined by
v = [tex]\frac{dx}{dt}[/tex]dx / dt
this definition serves for the instantaneous and the average velocity if the displacements are linear in time
v = 20/8
v = 2.5 m / s
b) for this part we use
v = [tex]\frac{\Delta x}{\Delta t}[/tex]
Δx = x_f -x₀
we must place a reference system, where the direction to the right is positive
x_f = -2 m
x₀ = +3 m
Δx = -2 -3
Δx = -5 m
we calculate
v = -5 / 10
v = -0.5 m / s
this value is a scalar
I’m giving 15 points for this one multiple choice question! Pls Help! It’s not A.
An electric food processor uses 250 joules of electrical energy every second. Due to friction and other causes, the energy available to spin the blades to cut food is reduced to 200 joules per second. The efficiency of the food processor is
A. 0.8%
B. 8%
C. 80%
D. 800%
What does the object below model?
O A. The heart
O B. The skeletal system
C. The brain
O D. The lungs
Answer: c
Explanation: it is c because i used my brain to answer it
Answer: The Brain
Explanation:
Its the brain
Consider two soap bubbles having radii r1 and r2 (r1 < r2) connected via a valve. What happens if we open the valve?
Answer:
Explanation:
The radius of the smaller bubble, r1 will decrease and that of the bigger bubble, r2 will increase.
The pressure that is present in the smaller bubble usually is greater than the pressure that exists inside that of the bigger bubble. This then makes air to flow from r1 to r2 thereby making the radius of the smaller bubble r1, to decrease while keeping that of the bigger bubble r2 higher.
an electric bulb is marked 40volts ,230w another bulb is marked 40w,110v
a.calculate the ratio of their resistance
b.the ratio of their energy
c.find the charge on each bulb
d.which of the two bulbs can hold enough .
Answer:
a. The ratio of their resistance is 2783:64
b. The ratio of their energy is 4:23
c. The charge on the first bulb is 5.75 C
The charge on the second bulb is [tex]0.\overline {36}[/tex] C
Explanation:
The voltage on one of the electric bulbs, V₁ = 40 volts
The power rating of the bulb, P₁ = 230 w
The voltage on the other electric bulbs, V₂ = 110 volts
The power rating of the bulb, P₂ = 40 w
a. The power is given by the formula, P = I·V = V²/R
Therefore, R = V²/P
For the first bulb, the resistance, R₁ = 40²/230 ≈ 6.96
The resistance of the second bulb, R₂ = 110²/40
The ratio of their resistance, R₂/R₁ = (110²/40)/(40²/230) = 2783/64
∴ The ratio of their resistance, R₂:R₁ = 2783:64
b. The energy of a bulb, E = t × P
Where;
t = The time in which the bulb is powered on
∴ The energy of the first bulb, E₁ = 230 w × t
The energy of the second bulb, E₂ = 40 w × t
The ratio of their energy, E₂/E₁ = (40 w × t)/(230 w × t) = 4/23
∴ The ratio of their energy, E₂:E₁ = 4:23
c. The charge on a bulb, 'Q', is given by the formula, Q = I × t
Where;
I = The current flowing through the bulb
From P = I·V, we get;
I = P/V
For the first bulb, the current, I = 230 w/40 V = 5.75 amperes
The charge on the first bulb per second (t = 1) is therefore;
Q₁ = 5.75 A × 1 s = 5.75 C
The charge on the first bulb, Q₁ = 5.75 C
Similarly, the charge on the second bulb, Q₂ = (40 W/110 V) × 1 s = [tex]0.\overline {36}[/tex] C
The charge on the second bulb, Q₂ = [tex]0.\overline {36}[/tex] C.
d. The question has left out parts
During which process does layer upon layer of sediment build up, exerting pressure on the layers below?
a. erosion
b. compaction
c. conglomerate
d. weathering
A KG object has a speed of 24 M/S if it has 14 J of kinetic energy what is the mass
A book is placed on a table and a bike moves on a road.
Which statement is correct?
Both the book and the bike have kinetic energy.
Both the book and the bike have potential energy.
The book has potential energy and the bike has kinetic energy.
The book has kinetic energy and the bike has potential energy.
The book has potential energy and the bike has kinetic.
kinetic energy is energy possessed when a object is in motion. The bike is moving. Therefore, it has kinetic energy. The book isn't moving. Hopefully that helped
A girl runs 40m due south in 40 seconds an d then 20m due north in 10 secondsCalculate.
the average speed,
her average velocity .
in her change in velocity for the whole journey!
The average speed of the girl is 1.2 m/s.
Average velocity is defined as the trade in position or displacement (∆x) divided by the time durations (∆t) wherein the displacement takes place. The common velocity can be effective or negative depending upon the sign of the displacement. The SI unit of average velocity is meters per second (m/s or ms-1).
Given;
Total distance = 40 + 20 = 60 M
Displacement = 40 - 20 = 20 m south
total time = 40 + 10 = 50 seconds
Average speed = total distance / total time
= 60/50
= 1.2 m/s
average velocity = total displacement / total time
= 20 / 50
= 0.4 m/s due south.
Average velocity is calculated by means of dividing your displacement (a vector pointing out of your initial role in your final position) through the entire time; the average pace is calculated by way of dividing the overall distance you traveled by means of the total time.
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These 2 processes cause watersheds to change.
Answer:
Change is an integral component of the watershed. The wide variations in river and stream flow regularly change shorelines, stream channels and stream corridors. Upland areas of watersheds also undergo changes due to ecological succession, disease, competition, human activity and other factors.
Explanation:
Which of the following are devices that utilize electromagnets? Select all that apply?
relay switches
doorbells
crane pulleys
security locks
what two factors directly affect the acceleration of an object?
The acceleration of an object depends on the mass of the object and the amount of the force applied to it. It states that the acceleration of an object increases with increased force and decreases with increased mass.
A man lifts a 5 Newton bag of groceries
from the floor to the top of the countertop,
which is 1.1 meters tall. What is the work
done by this person in lifting groceries?
5
5.5
4.5
6
Which statement describes the difference between metallic bonds and Van der Waals forces
Explanation:
Metallic bonds hold metal atoms and freely moving valence electrons together, while Van der Waals forces hold nonpolar molecules together. OD. Metallic bonds hold metal atoms and freely moving valence electrons together while Van der Waals forces hold atoms together when they share valence electrons.
The distance between two subway stations is 3 miles. If a train travels between the two stations at an average speed of 60 mph, how many minutes does it take for the train to finish the trip between the two stations?
Answer:3 minutes
Explanation:60 miles an hour, 60 minutes in an hour, 1 mile per minute
A chocolate bar has nutritional energy content of 100KJ. If an 50kg mountain climber eats this chocolate bar and converts it all to potential energy. What altitude(height) can she climb on a mountain using this energy? Consider g=10m/s^2
Answer:
h = 200 m
Explanation:
The energy content of the chocolate is completely converted to the potential energy of the climber. Therefore:
[tex]Energy\ of\ Chocolate = Potential\ Energy\\Energy\ of\ Chocolate = mgh[/tex]
where,
m = mass of climber = 50 kg
Energy of Chocolate = 100 KJ = 100000 J
g = acceleration due to gravity = 10 m/s²
h = height = ?
Therefore,
[tex]100000\ J = (50\ kg)(10\ m/s^2)h\\\\h = \frac{100000\ J}{500\ N}[/tex]
h = 200 m
A small block with mass 0.0350 kgkg slides in a vertical circle of radius 0.550 mm on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point AA, the magnitude of the normal force exerted on the block by the track has magnitude 3.90 NN . In this same revolution, when the block reaches the top of its path, point BB, the magnitude of the normal force exerted on the block has magnitude 0.670 NN . Part A How much work was done on the block by friction during the motion of the block from point AA to point BB
Answer:
W_net = μ 5.58, μ = 0.1 W_net = 0.558 J
Explanation:
The work is defined by the related
W = F. d = F d cos θ
where bold indicates vectors.
In the case, the work of the friction force on a circular surface is requested.
The expression for the friction force is
fr = μ N
the friction force opposes the movement, therefore the angle is 180º and the cos 180 = -1
W = - fr d
the path traveled half the length of the circle
L = 2 π R
d = L / 2
d = π R
we substitute
W = - μ N d
Total work is initial to
W_neto = - μ π R (N_b - N_a)
let's calculate
W_net = - μ π 0.550 (0.670 - 3.90)
W_net = μ 5.58
for the complete calculation it is necessary to know the friction coefficient, if we assume that μ = 0.1
W_net = 0.1 5.58
W_net = 0.558 J
Can you please answer my question correctly ASAP
Answer:
1) C, 2) C, 3) B, 4) D, 5) A/B, 6) D, 7) D, 8) A, 9) B, 10) A
Explanation:
1) Seconds, minutes and days are time units. (Correct answer: C)
2) The displacement is shortest distance between the point of origin and the point of destination. (Correct answer: C)
3) The velocity is the rate of change of position in time. (Correct answer: B)
4) Graphs are a very useful ressource to infer characteristics inherent to a studied physical variable. (Correct answer: D)
5) There are two possible answers, since both milimeters and meters are units for distance. (Correct answers: A/B)
6) The distance is the arc length of the entire path that object travelled. (Answer: D)
7) Traditionally, in a position vs. time graph we plot time in the x-axis. (Answer: D)
8) In this case, we use a distance-time graph, where travelled distance is the dependent variable and time is the independent variable. (Answer: A)
9) The point of origin is the initial position of the object. (Answer: B)
10) The point of destination is the final position of the object. (Answer: A)
A piece of steel is 11.5cm long at 22C. It is heated to 1221C, close to its melting point. How long is it, in cm, at the high temperature?
Answer:
The length at the final temperature is 11.7 cm.
Explanation:
We need to use the thermal expansion equation:
[tex]\Delta L=\alpha L_{0}\Delta T[/tex]
Where:
L(0) is the initial lengthΔT is the differential temperature, final temperature minus initial temperature (T(f)-T(0))ΔL is the final length minus the initial length (L(f)-L(0))α is the coefficient of linear expantion of steel (12.5*10⁻⁶ 1/°C)So, we have:
[tex]L_{f}-L_{0}=\alpha L_{0}(T_{f}-T_{0})[/tex]
[tex]L_{f}=L_{0}+\alpha L_{0}(T_{f}-T_{0})[/tex]
[tex]L_{f}=0.115+(12.5*10^{-6})(0.115)(1221-22)[/tex]
[tex]L_{f}=0.117\: m[/tex]
Therefore, the length at the final temperature is 11.7 cm.
I hope it helps you!
4. An automobile gasoline engine is able to do 225 J of useful work with each stroke of its
pistons. If the engine has an efficiency of 29%, what is the amount of work that must be done on
the pistons in the engine?
[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the concept of Efficiency.
We know that, efficiency is given as,
E (eta) = Output work / Input Work
hence, here, E = 29% and Output work = 225
hence, 29% = 29/100 in real..
hence, the work done on piston is given as,
29/100 = 225/I
therefore, I = 225*100/29 ==> I = 22500/29 ==> I = 775.8 joules
hence, the work done on the pistons is 775 J
Which chemical reaction is the fastest?
A. Mold grows on bread.
B. Bacteria make yogurt from milk.
C. Yeast produces air pockets in bread.
D. Baking soda produces bubbles when vinegar is poured on it.
Answer:
D. Baking soda produces bubbles when vinegar is poured on it.
Explanation:
Acetic acid = C₂H₄O₂
Baking soda = NaHCO₃
C₂H₄O₂ + NaHCO₃ → NaC₂H₃O₂ + H₂O + CO₂
When baking soda is added to vinegar, a chemical reaction will take place producing a huge amount of carbon-dioxide in the form of bubbles in the foaming mixture.
Which of the following refers to the concentration of a substance?
A.the maximum amount of a solute that can be dissolved in a solvent at a given temperature
B.the minimum volume of solvent dissolved per liter of solution at a given pressure
C.the grams of solute dissolved per 100 g of solvent
D.the size of the particles that make up a substance
The statement which refers to the concentration of a substance is the maximum amount of a solute that can be dissolved in a solvent at a given temperature. Thus, the correct option for this question is A.
What is a Substance?A substance may be defined as a type of chemical element and its compounds in the natural state or the result of a manufacturing process. In a manufacturing process, a chemical reaction is usually required in order to form a substance.
The concentration of a substance is the quantity of solute present in a given quantity of solution. Concentrations are usually expressed in terms of molarity, defined as the number of moles of solute in 1 L of solution.
Therefore, the maximum amount of a solute that can be dissolved in a solvent at a given temperature is a statement that refers to the concentration of a substance. Thus, the correct option for this question is A.
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a bed that has an area of 3.75 m2 and weighs 1,025N, what pressure would the bed exert on the floor?
Answer:
0.03964
Explanation:
Let us calculate the pressure exerted on the bottom by the weight of the fluid. That pressure is the weight of the fluid mg divided by the area A supporting it (the area of the bottom of the container): P=mgA P = mg A.
What are two ways fusion is used in the real world.
Answer:
The main application for fusion is in making electricity. Most fusion reactors make less radiation than the natural background radiation we live with in our daily lives. ... Clean - No combustion occurs in nuclear power (fission or fusion), so there is no air pollution.
NO LINKS!!!!!! Help its urgent, PLEASE HELP!!!!!!!!!!!!!!!!
Answer:
I think ur answer would be B
Explanation:
srry if wrong
hope this helps
i need help asap !
Work output has a force of 5 N and distance of 5 m. Work input has a force of 10 N and distance of 10 m. What is the efficiency?
100%
25%
125%
0.25%
Answer:
the answer is 100%!
your welcome
A skateboarder is traveling at a velocity of 8 m/s. She slows down and comes to a stop in 4 seconds. Calculate the skater’s acceleration.
Answer:
Go to this link it has many examples - https://staff.retsd.mb.ca/public/or4xe53elrzxg5ldmjuwe3i/Lists/SharedDocuments/Physics/14.2.PDF
Explanation:
Link ^
Water tends to moderate climate. Why is it warmer in the winter and cooler in the summer in cities located near the ocean or large lakes?
A.Water has a low specific heat and therefore changes temperature faster than most other substances.
B.Water has a low specific heat and therefore changes temperature slower than most other substances.
C.Water has a high specific heat and therefore changes temperature more slowly than most other substances.
D.Water has a high specific heat and therefore changes temperature more quickly than most other substances.
It is warmer in the winter and cooler in the summer in cities because water has high specific heat and therefore changes temperature more slowly than most other substances. The correct option is C.
What is climate?Climate is the average weather over a longer period of time in a particular area. A description of a climate includes details such as the typical temperature in each season, the amount of rainfall, and the amount of sunshine.
Coastal weather tends to be more moderate than continental weather, with fewer hot and cold extremes, because the ocean warms and cools more slowly than the atmosphere.
The majority of rain clouds are produced by ocean evaporation, particularly in the tropics, which affects where wet and dry regions on land are located.
Therefore, the correct option is C. Water has a high specific heat and therefore changes temperature more slowly than most other substances.
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Help pls sand quickly plssssss
Answer:
The magnet produces an electric current in the wire
Explanation:
Answer: the first one is right
Explanation:
principle of quantization of charge
Answer:
Quantization is the process of replacing analog samples with approximate values taken from a finite set of allowed values.
Explanation:
Which of the following is not a unit of volume?
A. L
B. mL
C. m^3
D. cm^2
Explanation:
D. cm^2
It's a unit for quadruple centimeters. All of the others are used to charge the amount of water in a specific bowl etc.