Using 3rd equation of kinematics
[tex]\boxed{\Large{\sf v^2-u^2=2as}}[/tex]
[tex]\\ \Large\sf\longmapsto v^2=u^2+2as[/tex]
[tex]\\ \Large\sf\longmapsto v^2=24^2+2(4)(96)[/tex]
[tex]\\ \Large\sf\longmapsto v^2=576+768[/tex]
[tex]\\ \Large\sf\longmapsto v^2=1344[/tex]
[tex]\\ \Large\sf\longmapsto v=\sqrt{1344}[/tex]
[tex]\\ \Large\sf\longmapsto v=36.6m/s[/tex]
John walked a distance of 900 meters in 10 minutes what was his average speed in kilomerters per hour
Answer:
5.4
Explanation:
900/10=90 and 90(60)=5400 meters. 5400/100=5.4
why do flames go upwards
Answer:
Easy search it on g o o g l e
10. Match the following varibles to their relationship in Newton's 2nd Law. Questions 1. Force and Acceleration 2. Mass and Acceleration 3. Speed and Distance Answer Choices A. Direct Relationship B. Inverse Relationship C. Not in Newton's 2nd Law
Explanation:
based on the above information
1.A
2.B
3. C
A washing machine heats 10kg of water in each wash cycle. How much energy is saved by washing at 30'c instead of 50'c if the starting temperature of the cold water is 16'c? The specific heat capacity of water is 4200 J/Kg'c
Answer:
[tex]8.4 \times 10^{5}\; \rm J[/tex], assuming that there's no heat exchange between the washing machine and the environment.
Explanation:
Let [tex]m[/tex] denote the mass of water and [tex]c[/tex] the specific heat capacity of water. The energy required to raise the temperature of that much water by [tex]\Delta T[/tex] would be:
[tex]Q = c \cdot m \cdot \Delta T[/tex].
Washing at [tex]30\; \rm ^{\circ} C[/tex] would require a temperature change of [tex]\Delta T = 30\; \rm ^{\circ} C - 16\; ^{\circ} \rm C = 14\; \rm K[/tex].
Washing at [tex]50\; \rm ^{\circ} C[/tex] would require a temperature change of [tex]\Delta T = 50\; \rm ^{\circ} C - 16\; ^{\circ} \rm C = 34\; \rm K[/tex].
In both situations, [tex]c = 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1}[/tex] while [tex]m = 10\; \rm kg[/tex].
Calculate the energy required in either situation:
Washing at [tex]30\; \rm ^{\circ} C[/tex]:
[tex]\begin{aligned}& Q({30\; ^{\circ} {\rm C}}) \\ &= c \cdot m \cdot \Delta T \\ &= 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1} \times 10\; \rm kg \times 14\; \rm K \\ &= 588000 \times 10^{5}\; \rm J\end{aligned}[/tex].
Washing at [tex]50\; ^{\circ} {\rm C}[/tex]:
[tex]\begin{aligned}& Q({50\; ^{\circ} {\rm C}}) \\ &= c \cdot m \cdot \Delta T \\ &= 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1} \times 10\; \rm kg \times 34\; \rm K \\ &= 1428000 \; \rm J\end{aligned}[/tex].
[tex]1428000\; \rm J - 588000\; \rm J = 8.4 \times 10^{5}\; \rm J[/tex].
Please please helpjejejnebwbww
Answer:
C. 540 N
Explanation:
Let suppose that system formed by the athlete and the load are in equilibrium. By Newton's Laws of Motion, we use the moment equation with respect to the feet of the athlete to determine the upward force exerted by his two arms:
[tex]\Sigma M = -F\cdot r_{1} + m_{L}\cdot g \cdot r_{2} + m_{A}\cdot g \cdot r_{3} = 0[/tex]
[tex]F = \frac{(m_{L}\cdot r_{2} + m_{A}\cdot r_{3})\cdot g}{r_{1}}[/tex] (1)
Where:
[tex]m_{L}[/tex] - Mass of the load, in kilograms.
[tex]m_{A}[/tex] - Mass of the athlete, in kilograms.
[tex]g[/tex] - Gravitational acceleration, in meters per square second.
[tex]r_{1}[/tex], [tex]r_{2}[/tex], [tex]r_{3}[/tex] - Distances with respect to the feet, in meters.
[tex]F[/tex] - Upward force exerted by his two arms, in newtons.
If [tex]m_{L} = 6\,kg[/tex], [tex]r_{2} = 1.20\,m[/tex], [tex]m_{A} = 70\,kg[/tex], [tex]r_{3} = 0.90\,m[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]r_{1} = 1.30\,m[/tex], then the upward force is:
[tex]F = \frac{[(6\,kg)\cdot (1.20\,m)+(70\,kg)\cdot (0.90\,m)]\cdot \left(9.807\,\frac{m}{s^{2}} \right)}{1.30\,m}[/tex]
[tex]F = 529.578\,N[/tex]
The upward force exerted by his two arms is 529.578 newtons. (Right answer: C)
If 20N force produces an acceleration of 5ms^-2 In a body then the mass of the body will be:
A.4kg
B.5kg
C.1/4kg
D.1/5kg
The electrical resistance of an element in a platinum resistance thermometer at 100°c, 0°c and room temperature are 75.00Ω, 63.00Ω and 64.992Ω respectively. Use the data to calculate room temperature
Answer:
16.6 °C
Explanation:
From the question given above, the following data were obtained:
Temperature at upper fixed point (Tᵤ) = 100 °C
Resistance at upper fixed point (Rᵤ) = 75 Ω
Temperature at lower fixed point (Tₗ) = 0 °C
Resistance at lower fixed point (Rₗ) = 63.00Ω
Resistance at room temperature (R) = 64.992 Ω
Room temperature (T) =?
T – Tₗ / Tᵤ – Tₗ = R – Rₗ / Rᵤ – Rₗ
T – 0 / 100 – 0 = 64.992 – 63 / 75 – 63
T / 100 = 1.992 / 12
Cross multiply
T × 12 = 100 × 1.992
T × 12 = 199.2
Divide both side by 12
T = 199.2 / 12
T = 16.6 °C
Thus, the room temperature is 16.6 °C
A tennis player hits a ball hard and 0.80 seconds later hears the echo from a wall. The speed of sound in air is 340m/s how far away is the player from the wall
Answer:
136 m.
Explanation:
From the question given above, the following data were obtained:
Time (t) = 0.80 s
Speed of sound (v) = 340 m/s
Distance (x) =?
The distance of the player from the wall can be obtained as follow:
v = 2x / t
340 = 2x / 0.80
Cross multiply
2x = 340 × 0.80
2x = 272
Divide both side by 2
x = 272 / 2
x = 136 m
Thus, the distance of the player from the wall is 136 m
A cyclist competes half round of a circular track of a diameter 636m in 1.5 minutes . find the velocity
Answer:
Given information:-
Radius of the circular track is 636 mThe time elapsed in the journey is 1.5 min or 90 sThe distance traveled by the cyclist is semi circumference of the circle = πr[tex]\clubsuit[/tex]The displacement of the cyclist will be shortest distance from his initial to final positions which is nothing but diameter of the circle = 2r
We know that,
[tex] \underline{ \boxed{ \sf{Speed = \frac{Distance \: covered }{Time \: taken}}}}[/tex]
[tex]\longrightarrow \sf{\frac{636 \times 3.14 m}{90s}} \\ \\ \longrightarrow \sf22.18 m/s[/tex]
Speed of the cyclist is 22.18 m/s[tex]\sf{Velocity = \frac{Displacement }{ Time} }[/tex]
[tex]\longrightarrow \sf{ \frac{2 \times 636m}{90s} } \\ \\ \longrightarrow \sf{14.13 \: m/s}[/tex]
Velocity of the cyclist is 14.13 m/sThank You :)
HELP‼️‼️ A car horn creates a 595 Hz tone at rest. Two cars pass on the street, each going 20.0 m/s; the first car honks. What frequency does the other car hear before they pass each other?
The frequency of the other car is 669HZ
Let start off by writing out the parameters given in the question
frequency= 595 HZ
Speed of sound(v)= 343m/s
Speed of the car(vs)= 20m/s
Speed of the second car(vo) = 20m/s
The frequency of the other car can be calculated as follows
(v+vo/v-vs) f
= (343+20/343-20)595
= (363/323)595
= 1.1238(595)
= 669 HZ
Hence the frequency of the other car is 669 HZ
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.........도움......
Is this correct? (the option is marked)
Answer:
sorry I don't understand this language
a.
quuntlity.
Answer the following questions.
What is force? Write down its SI unit.
b. Name
any five types of force.
c.
What is pulling force? Give any two examples.
d. What is centripetal force? Give one example of centrifugal force.
What is gravitational force? Give two examples.
f. What is magnetic force? How is this force useful to us?
Answer:
1) Force is the action of pull or push that changes or tends to change the position of a body. Its SI unit is newton.
2) The types of force are:
• Pulling and Pushing force
• Frictional force
• Gravitational force
•Muscular force
• Centripetal and Centrifugal force
: Chuyển động Một vật xuất phát từ A chuyển động đều về B cách A 240 m với vận tốc 10 m/s. Cùng lúc đó, một vật khác chuyển động đều từ B về A. Sau 15 s hai vật gặp nhau. Tìm vận tốc của vật thứ hai và vị trí hai vật gặp nhau.
20 The metal surface of a kettle is hot. What happens to the cool air outside the kettle when it comes into contact with the hot kettle?
A The density of the air decreases and the air falls.
B The density of the air decreases and the air rises.
C The density of the air increases and the air falls.
D The density of the air increases and the air rises.
D. The density of the sir increases and the air rises.
When coming in contact with the kettle, it becomes hot, it expands and rises up, due to lesser density as compared to the surrounding air.
una caja en reposo se traslada 93 cm con un peso de 67N en un tiempo de 9,89h.¿cual es la aceleración la masa y la fuerza de dicho objeto
Answer:
a. Acceleration, a = 1.47 * 10^{-9} m/s²
b. Mass = 4.57 * 10^{10} kilograms
c. Force = 67.12 Newton
Explanation:
Given the following data;
Distance = 93 cm to meters = 93/100 = 0.93 meters
Weight = 67 N
Time = 9.89 hours to seconds = 35604 seconds
Initial velocity = 0 m/s (since it's starting from rest)
Acceleration due to gravity, g = 9.8 m/s
a. To find the acceleration, we would use the second equation of motion;
[tex] S = ut + \frac{1}{2} at^{2} [/tex]
Where;
S is the distance covered or displacement of an object.
u is the initial velocity.
a is the acceleration.
t is the time.
Substituting the values into the equation, we have;
[tex] 0.93 = 0*35604 + \frac{1}{2} * a*35604^{2} [/tex]
[tex] 0.93 = 0 + \frac{1}{2} * 1267644816a [/tex]
[tex] 0.93 = 633822408a [/tex]
[tex] Acceleration, a = \frac{0.93}{633822408} [/tex]
Acceleration, a = 1.47 * 10^{-9} m/s²
b. To find the mass
Weight = mass * acceleration due to gravity
67 = mass * 1.47 * 10^{-9}
[tex] Acceleration, a = \frac{67}{1.47 * 10^{-9}} [/tex]
Mass = 4.57 * 10^{10} kilograms
c. To find the force;
Force = mass * acceleration
Force = 4.57 * 10^{10} * 1.47 * 10^{-9}
Force = 67.12 Newton
A man pulls his luggage on a 30 degree incline with a constant force of 25 N. How
much work does he do after walking 20.0 m?
a) 430 J
b) 330J
c) 1500J
d) 250 J
We know
[tex]\boxed{\sf W=Fscos\theta}[/tex]
[tex]\\ \sf\longmapsto W=25(20)cos30°[/tex]
[tex]\\ \sf\longmapsto W=500\times \dfrac{\sqrt{3}}{2}[/tex]
[tex]\\ \sf\longmapsto W=250\sqrt{3}[/tex]
[tex]\\ \sf\longmapsto W=250(1.73)[/tex]
[tex]\\ \sf\longmapsto W\approx 430J[/tex]
Option a) 430 J work done he do after walking 20.0 m.
What is work?Work, in physics, is a measure of energy transfer that happens when an object exists moved over a distance by an external force at least part of which exists involved in the direction of the displacement.
Displacement exists as the distance moved in a straight line, in a provided direction, from the starting point. Displacement exists as a vector quantity as it includes size and direction.
An angle stands the figure formed by two rays, named the sides of the angle, sharing a standard endpoint, named the vertex of the angle.
Force=F=25NDisplacement=s=20mAngle=30°⇒[tex]W=Fcos\theta[/tex]
⇒[tex]W=25(20)cos 30^{0}[/tex]
Then,
⇒[tex]W=50*\sqrt{3} /2[/tex]
⇒[tex]W=250\sqrt{3}[/tex]
Hence,
⇒[tex]W=250(1.73)[/tex]
[tex]W[/tex] approximately 430J.
Hence, Option a) 430 J work done he do after walking 20.0 m.
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Can someone pls help, thank you in advance!
What is an example of a force applied at an angle to displacement
Answer:
an object sliding down hill
Explanation:
On a slope, the force applied is due to gravity. Its direction is straight down. If the object is sliding down the hill, its displacement is at an angle to the applied force. The angle of displacement will depend on the steepness of the hill.
mention various medium level and higher level human resources related to engineering.
Answer:
Higher-level human resources related to engineering are those who:
Assist other engineers with solving complex problems. Work with management to keep the project on track. Mentor younger engineersMedium Level engineers will normally comprise the following:
They are responsible for developing engineering plans and performing calculations with respect to the same. Project workflow management Engineering Support facilitation Project Reporting Coordination of Team MembersCheers
Lightning a. occurs when a positively charged cloud base induces a negative charge on the Earth's surface. b. travels most often from cloud to ground and cannot travel from cloud to cloud. c. may be accompanied by the sound of explosively expanding hot air, called thunder. d. involves a conductive path or leader of positive ions from cloud to ground.
Answer:
c. may be accompanied by the sound of explosively expanding hot air, called thunder.
Explanation:
Lightning is a discharge which is due to the reaction between oppositely charged charges in the clouds, or between clouds base and the Earth surface.
The motion of the cloud causes charging of clouds by friction, thus the reaction between opposite charges (jumping of charges from one cloud to another) in the cloud can lead to lightning. Also, oftentimes the bottom of a cloud is negatively charged so that this is attracted to the positive charge on the earth surface. Thus leading to a discharge called lightning.
Thus in the given question, the appropriate option is C. This implies that, lightning may be accompanied by the sound of explosively expanding hot air, called thunder.
Lifestyle practice that can improve your quality of life
Explanation:
And keep changing gradually.
Eat a variety of foods. ...
Base your diet on plenty of foods rich in carbohydrates. ...
Replace saturated with unsaturated fat. ...
Enjoy plenty of fruits and vegetables. ...
Reduce salt and sugar intake. ...
Eat regularly, control the portion size. ...
Drink plenty of fluids. ...
Maintain a healthy body weight
A person climbs out of swimming pool and stands in the open air.Explain why evaporation of water from the surface of the persons body causes the person to feel cold
Answer:
The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.
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3. There is a bell at the top of a tower that is 45 m high. The bell weighs 64 kg. The
bell has joules of potential energy.
Answer:It has 8550 j energy
A long distance runner running a 5.0km track is pacing himself by running 4.5km at 9.0km/h and the rest at 12.5km/h. What is his average speed?
Answer:
9.26 km/h
Explanation:
Applying,
V' = D'/t'............... Equation 1
Where V' = Average speed, D' = Total distance, t' = total time.
Given: D' = 5 km
But,
v = d/t............ Equation 2
Where v = speed , d = distance, t = time
t = d/v............ Equation 3
Given: d = 4.5 km, v = 9 km/h, and d = 0.5 km, v = 12.5 km/h
Therefore,
t₁ = 4.5/9 = 0.5 hours
t₂ = 0.5/12.5
t₂ = 0.04 hours
Therefore,
V' = 5/(0.5+0.04)
V' = 5/0.54
V' = 9.26 km/h
J.J. Thomson theorized that, if an atom had all of its negatively charged
electrons removed, the remaining material would be
A. neutral
B. negatively charged
C. positively charged
D. magnetic
Answer:
C. Positively charged
Explanation:
The plum pudding model of the atom proposes by J. J. Thomson consisted of electrons which lay embedded as the raisins within a dough or soup that was positively charged. The electron was discovered by J. J. Thomson in 1897 through cathode ray tube experiments.
Based on the plum pudding model, if all the negatively charge electrons contained in an atom are removed, the material remaining will be the positively charged soup
After release of jet, energy is lost by the engine. How principle of conservation of energy is obeyed in this condition.
Answer:
The principle of conservation of energy states that in a closed system, the energy can neither be created nor destroyed between interacting particles and remains constant or transformed from one form to another
In the jet engine, the release of jet changes the number of interacting particles in the engine, and given that energy cannot be created in the instantaneously closed system of the engine, energy is carried away and therefore lost by particles in the jet exhaust
The conservation of energy principle is therefore obeyed in the condition in which the jet engine losses energy by the release of jet
Explanation:
A group of students are designing a field study to investigate the length of time a traffic light remains yellow.
Answer:
3 to 7 seconds.
Explanation:
According to the traffic engineers the length or the duration of the signal to turn form yellow or amber to green is more than 5 seconds. A time interval is needed to easy out the traffic flow.A water heater marked 4 kW takes 4 minutes to heat 1 kg of water from 20 °C to 50 °C. The cost of electrical energy per kWh
is $0.120. What will be the total cost of energy consumption?
The total cost of the energy consumption for the given time period is $0.0364
The given parameters include;
power rating of the heater, P = 4 kW = 4000 Wtime taken to completely boil the water,[tex]t = 4 \min = 4 \min \times \frac{1 \ h}{60 \ \min} = 0.067 \ h[/tex]mass of the water, m = 1 kginitial temperature of the water, t₁ = 20 ⁰Cfinal temperature of the water, t₂ = 50 ⁰Cspecific heat capacity of water, c = 4200 J/kg⁰Ccost of electrical energy = $0.12The total energy consumed in the process of heating the water;
Total electrical Energy = Energy of the heater (kWh) + Energy of the heated water (kWh)
Energy of the heater (kWh) = power x time
= 4 kW x 0.067 h
= 0.268 kWh
Energy of the heated water (J) = mcΔt
where;
Δt is the change in temperature = t₂ - t₁
= 50 ⁰C - 20 ⁰C = 30⁰C
Energy of the heated water (J) = 1 x 4200 x 30
= 126,000 J
Electrical power of the heated water (Watts) = [tex]\frac{126,000 \ J}{4 \ \min} \times \frac{1 \min}{60 \ s} = 525 \ W[/tex]
Energy of the heated water (kWh) = [tex]\frac{525}{1000} \times 4\min\times \frac{1 \ hr}{60 \min} = 0.035 \ kWh[/tex]
Total electrical Energy = 0.268 kWh + 0.035 kWh
= 0.303 kWh
The total cost of the energy consumed is calculated as;
[tex]Total \ cost = \frac{\$ \ 0.12}{kWh} \times 0.303 \ kWh = \$ \ 0.0364[/tex]
Therefore, the total cost of the energy consumption is $0.0364
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Explain why some of the tree get detached from a tree if we vigorously shake it's Branch.
Answer:
When a tree is vigorously shaken, the branches of the tree come in motion but the leaves tend to continue in their state of rest due to inertia of rest. As a result of this, leaves get separated from the branches of the tree and hence fall down.
Answer:
When a tree is vigorously shaken, the branches of the tree come in motion moving left and right and shake the leaves off, that's why some of the tree got detached when we vigorously shake its branch.
Explanation:
Like I did in the answer section.
Resistivity of metallic wire
depends on
*
It's length
It's shape
It's thickness
Nature of material
Answer:
nature of material
hope this help you
Many people believe that if the human race continues to use energy as we are now, without change, we'll witness a significant worldwide environmental impact in this century. Research this topic and discuss this possibility. Include concrete examples of specific environmental consequences of global warming.
Answer:
It is correct to say that if the human race continues to use energy as it is now, without change, we will witness negative environmental impacts around the world in this century.
As a concrete example, we can cite the means of transport that use fossil fuels, such as cars and buses, which release polluting gases into the atmospheric layer and cause the greenhouse effect, contributing to global warming.
To solve these problems, it is necessary to raise the awareness of individuals, so that there is more and more interest and search for environmentally responsible solutions, such as the large-scale production of electric cars, which do not pollute the environment.
