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
which statement accurately describes how the acceleration of an object in free fall changes
Answer:
A ball rolls off the table and free falls to the ground. Which statement accurately describes its acceleration? Its acceleration is downward but remains a constant value as it falls.
3kg of water at 80degree celcius is added to 8 kg of water at 25 degree celcius. find the temperature of final mixture provided there is no loss of heat in the surrounding. the specific heat capacity is 4200j/kg
Answer:
hope fully it help s
Observe the given figure and find the the gravitational force between m1 and m2.
Answer:
The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N
Explanation:
The details of the given masses having gravitational attractive force between them are;
m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m
The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;
[tex]F =G \cdot \dfrac{m_{1} \cdot m_{2}}{r^{2}}[/tex]
Where;
F = The gravitational force between m₁ and m₂
G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²
r₂ = 0.1 m + 0.15 m = 0.25 m
Therefore, we have;
[tex]F = 6.67430 \times 10^{-11} \ N \cdot m^2/kg \times \dfrac{20 \ kg\times 50 \ kg}{(0.1 \ m+ 0.15 \ m)^{2}} \approx 1.06789 \times 10^{-6} \ N[/tex]
The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N
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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A car travels first 10 km in 20 minutes and another 10 km in 30 minutes. What is the average speed of the car in m/s?
Total distance = 10 km + 10 km = 20 km
1 km = 1000 m
20km x 1000 = 20,000 m
Total time = 20 min. + 30 min. = 50 minutes
Average speed = Distance / time
Average speed = 20,000/50 min
Average speed = 400 m/s
3 write the three laws given by kepler.How did they help Newton to arrive at the inverse square law of gravity?
Answer:
Kepler's laws apply: First Law: Planetary orbits are elliptical with the sun at a focus. Second Law: The radius vector from the sun to a planet sweeps equal areas in equal times. Third Law: The ratio of the square of the period of revolution and the cube of the ellipse semimajor axis is the same for all planets.
cho 11,2 lit hỗn hợp gồm metan và etilen tác dụng với dung dịch brom. sau phản ứng xảy ra toàn thấy có chất khí thoát ra và 40 gam brom tham gia phản ứng .
a) viết phương trình phản ứng xảy ra
b) tính thành phần phần trăm thể tích mỗi chất trong hỗn hợp
c) đốt cháy toàn bộ thể tích khí thoát ra sau đó cho chất khí thu được tác dụng với 100ml dung dịch Ca(OH)2 1,25 M. tính khối lượng chất thu được sau phản ứng . biết metan ko tác dụng với brom , các chất khí đo ở điều kiện tiêu chuẩn
A cricket ball of mass 800g has momentum of 20 kg m/sec . Calculate velocity of ball
Answer: 25 m/s
Explanation:
1. rearrange equation p = mv to find v
2. v = p/m - then convert 800 g into kg (= 0.8 kg)
3. plug in p and m - v = 20 / 0.8 = 25 m/s
Answer:
V= 25m/s
Explanation:
Mass=800g
Momentum=20kgm/s
V= ?
Convert 800g to kg
800/1000 = 0.8kg
Momentum=mass× Velocity
Momentum/Mass = Velocity
20/0.8 =25m/s
Enlight the contribution of science and technology for current pandemic of Corona virus??
The vaccine ofcourse. They helped in making the vaccine.
any correct ans guess for 30 pts and brainlist
Answer:
a) ii
b) i
c)iii
d)iii
e) i
f)iii
Explanation:
i hope this will help
Answer:
the answer of b is N and d is mol
A compound eye __________. ANSWER Unselected is composed of thousands of prisms that focus light onto only a few photoreceptor cells Unselected All of the listed responses are correct. Unselected works best for resolving stationary images Unselected contains many individual light detectors, each with its own lens Unselected is possessed only by insect
Answer:
contains many individual light detectors, each with its own lens
Explanation:
The compound eye is found mainly in insects and crustaceans, it is composed of individual receptor units, each with its focus, sensing nerve; each one gives a small image of the environment, so the image is mosaic type, not a complete integral image of the environment.
When reviewing the different statements, the correct one is
contains many individual light detectors, each with its own lens
1
An object has a gravitational potential energy of
41772.5J and has a mass of 1550kg. How high is
it above ground?
Answer:
h = 2.78 m
Explanation:
Potential Energy(PE)
Mass(m)
Gravity(g) which is approximately equal to 10.
Height (h)
PE = mgh
41772.5 = 1500 * 10 * h
41772.5 = 15000h
h = 41772.5/15000
h = 2.78 m
An object moving north with an initial velocity of 14 m/s accelerates 5 m/s2 for 20 seconds. What is the final velocity of the object?
39 m/s
90 m/s
114 m/s
414 m/s
Answer:
option C
Explanation:
Final velocity of the object is 114 m / s. Hence, final velocity of the object is 114 m / s.
A 6.0 kg mass is placed on a 20º incline which has a coefficient of friction of 0.15. What is the acceleration of the mass down the incline? show all work please
Answer:
Explanation:
The form of Newton's 2nd Law that we use for this is:
F - f = ma where F is the Force pulling the mass down the ramp forward, f is the friction trying to keep it from moving forward, m is the mass and a is the acceleration (and our unknown).
We know mass and we can find f, but we don't have F. But we can solve for that by rewriting our main equation to reflect F:
[tex]wsin\theta-\mu F_n=ma[/tex] That's everything we need.
w is weight: 6.0(9.8). Filling in:
6.0(9.8)sin20 - .15(6.0)(9.8) = 6.0a and
2.0 × 10¹ - 8.8 = 6.0a and
11 = 6.0a so
a = 1.8 m/s/s
From the description of the question, the acceleration is 1.95 ms-2.
What is friction?The term friction is defined a the force that seeks to prevent the movement of a surface on another.
Now we know that;
ma =mgsinθ - ukmgcosθ
ma =( 6 * 9.8 * sin 20) - ( 0.15 * 6 * 9.8 * cos 20)
a = ( 6 * 9.8 * sin 20) - ( 0.15 * 6 * 9.8 * cos 20) /6
a = 20 - 8.29/6
a = 1.95 ms-2
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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.
Wat is acceleration!!!!!
Answer:
Acceleration is the rate of change of velocity with time.its system international unit is meters per second square.
I hope this helps
Si la fuerza de fricción cinetica es 250N ¿Qué fuerza se necesita para mantener a la caja deslizándose a una velocidad constante ¿
Answer:
250N
Explanation:
According to newton second law,
\sumF = ma
Fm - Ff = ma
Since the velocity is constant, a = 0m/s
Frictional force Ff = 250N
Substitute
Fm - 250 = m(0)
Fm - 250 = 0
Fm = 250N
Hence the force to keep the box sliding at constant speed is 250N
Which type of electromagnetic wave is deliberately used in some
circumstances to cause damage to living cells in the human body?
A. Infra-red
B. Gamma rays
C. Microwaves
D. Radio waves.
Gamma rays
used in radiotherapy
What will happen to the velocity and momentum of each ball when the small ball hits the heavier large ball?
The small ball will transfer its momentum to the heavier ball. Since the momentum gets conserved. The velocity will depend upon the mass of the balls.
What is the law of conservation of momentum?According to the law of conservation of momentum. The momentum of the body before the collision is always equal to the momentum of the body after the collision.
The momentum of the body is given by the product of the mass and velocity of the body.
According to the law of conservation of momentum
Momentum before collision =Momentum after collision
Hence the small ball will transfer its momentum to the heavier ball.
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A person slaps her leg with her hand, which results in her hand coming to rest in a time interval of 2.25 ms2.25 ms from an initial speed of 4.25 m/s4.25 m/s . What is the magnitude of the average contact force exerted on the leg, assuming the total mass of the hand and the forearm to be 1.75 kg1.75 kg
Answer:
The force is 3305.6 N.
Explanation:
Final velocity, v = 0
time, t = 2.25 ms
initial velocity, u = 4.25 m/s
mass, m = 1.75 kg
Let the acceleration is a.
Use first equation of motion.
v = u + a t
0 = 4.25 + a x 0.00225
a = - 1888.9 m/s^2
The force is
F = ma
F = 1.75 x 1888.9
F = 3305.6 N
which is not a common theory on how the effects of hypnosis occurs
Answer:
EFFECTS Adverse reactions to hypnosis are rare, but may include: Headache. Drowsiness. Dizziness
byeeeeeeeeeeeejdiiwidjwdjj2xi2idiwidisididie
Answer:
Be serious or else CEO of brainly will kick you out
Why aren’t magazine photos a good representation of what a healthy person looks like
Una partícula efectúa un MAS cuya ecuación es: x=0,3 cos (2t + /6) m. Determinar: Amplitud, frecuencia angular, fase inicial, periodo, frecuencia de oscilación y posición en t=0,25 s
Answer:
The answer is below
Explanation:
Una partícula efectúa un MAS cuya ecuación es: x=0.3cos (2t + π/6) m. Determinar: Amplitud, frecuencia angular, fase inicial, periodo, frecuencia de oscilación y posición en t=0.25 s
Solution:
La ecuación de la onda es:
x = A cos (ω t + Ф), donde:
A = amplitud, ω = frecuencia angular = 2 π / T = 2 π f, Ф = fase inicial, f = frecuencia, T = período
Por lo tanto, comparando la ecuación de la onda con x = 0.3cos (2t + π / 6), obtenemos:
a) A = 0.3
b) ω = 2 rad / s
c) Ф = π / 6 rad
d) ω = 2π / T
2 = 2π / T
T = 3.14 s
e) ω = 2πf
2 = 2πf
f = 0.32 Hz
f) en t = 0.25 s:
x (t) = 0.3cos (2 * 0.25 + π / 6) = 0.22 m
the diameter of circular park is 80 m find its area
Plz Help me thank uuu...
Which of these is a likely impact of the stronger than normal trade winds on the eastern Pacific ocean?
Warm surface water builds up, causing lower than average temperature.
Warm surface water builds up, causing higher than average temperature.
Warm surface water is reduced, causing colder conditions than normal.
Warm surface water is reduced, causing hotter conditions than normal.
Answer:
Jet stream would be displaced southwards causing heavy rain and flooding.
Explanation:
The other options of the question were A) Jet stream would be displaced northwards causing drought. B) Jet stream would be displaced southwards causing drought. D) Jet stream would be displaced northwards causing heavy rain and flooding,
The statement that is a likely impact of stronger than normal trade winds in the Pacific Northwest to the United States is "Jet stream would be displaced southwards causing heavy rain and flooding."
We are talking about climate or weather terminology. In this case, we are referring to the "El Niño" (the Children) effect. Its presence affects the weather in North America. This phenomenon combines with the "La Niña) effect and it presents itself every two to seven years, ad they last from 8 to 12 months, affecting the weather conditions of the region.
Answer:
jet stream should be displaced southwards which causes heavy rainfall and flood.
Give reason.
b} String roller is an example of wheel and axel .Why?
Explanation:
string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.
hence the we apply force on the roller and the string gets tight.
what is velocity give its SI unit
Answer:
Velocity is the speed of something given in a direction. the SI unit of velocity is metre per second or m/s.
Why are road accidents at high speeds very much worse than road accidents at low speeds?
Answer:
The momentum makes it worse.
Explanation:
The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.
