Answer:
A
Explanation:
Answer:
D. Conduction
Explanation:
Convection heat transfer occurs in fluids, while conduction heat transfer occurs in solids.
A 50kg refrigerator is being moved across a kitchen floor with an applied force of
300N. There is a known friction force of 50N acting against the motion of the
refrigerator.
What was the acceleration of the refrigerator? [ Select ]
m/s2
Answer:
5m/s²
Explanation:
Given parameters:
Mass of refrigerator = 50kg
Applied force = 300N
Frictional force = 50N
Unknown:
Acceleration of the refrigerator = ?
Solution:
To solve this problem:
Net force = m x a
m is the mass
a is the acceleration
Net force = Applied force - Frictional force
300 - 50 = 50 x a
250 = 50 x a
a = 5m/s²
How many miles per day can you walk at a MODERATE Intensity level and your heart rate is 170?
Answer:
Not enough detail as it is very defendant on the person and a bunch of factors in health, but overall your heart rate shouldn't reach 170 as an adult walking at a moderate intensity level, that would be closer to extreme intensity.
Explanation:
what is the result of seafloor spreading?
Answer:
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
Explanation:
eventually the crust cracks.
Heather drives her Super-Beetle around a turn on a circular track which has a radius of 200 m. The Super-Beetle has a mass of 1500 kg and the coefficient of static friction between the road and tires is 0.6.
a. What is the force of static friction the road can apply batore the car starts to selon (use Ft= uFn).
b. What is the maximum speed the car can travel before it would start to slide?
Answer:
a) The force of static friction the road can apply before the car starts to move is 8826.3 newtons.
b) The maximum speed that a car can travel before it would start to slide is approximately 34.305 meters per second.
Explanation:
a) Let suppose that the car is on a horizontal ground and travels at constant speed. The vehicle experiments a centripetal acceleration due to friction, which can be seen in the Free Body Diagram (please see image attached for further details). By Newton's Laws, we construct the following equations of equilibrium:
[tex]\Sigma F_{x} = \mu_{s}\cdot N = m\cdot \frac{v^{2}}{R}[/tex] (1)
[tex]\Sigma F_{y} = N -m\cdot g = 0[/tex] (2)
Where:
[tex]\mu_{s}[/tex] - Static coefficient of friction, dimensionless.
[tex]N[/tex] - Normal force from ground to the car, measured in newtons.
[tex]v[/tex] - Maximum speed of the car, measured in meters per second.
[tex]R[/tex] - Radius of the circular track, measured in meters.
[tex]m[/tex] - Mass, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
By applying (2) in (1):
[tex]\mu_{s}\cdot m\cdot g = m\cdot \frac{v^{2}}{R}[/tex] (3)
The force of static friction the road can apply in the car ([tex]f[/tex]), measured in newtons, is: ([tex]\mu_{s} = 0.6[/tex], [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex])
[tex]f = \mu_{s}\cdot m \cdot g[/tex]
[tex]f = (0.6)\cdot (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)[/tex]
[tex]f = 8826.3\,N[/tex]
The force of static friction the road can apply before the car starts to move is 8826.3 newtons.
b) Then, we calculate the maximum speed of the car by (3):
[tex]\mu_{s}\cdot m\cdot g = m\cdot \frac{v^{2}}{R}[/tex]
[tex]\mu_{s}\cdot g = \frac{v^{2}}{R}[/tex]
[tex]v = \sqrt{\mu_{s}\cdot g\cdot R}[/tex]
If we know that [tex]\mu_{s} = 0.6[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]R = 200\,m[/tex], then the maximum speed of the car can travel before it would start to slide is:
[tex]v =\sqrt{(0.6)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (200\,m)}[/tex]
[tex]v \approx 34.305\,\frac{m}{s}[/tex]
The maximum speed that a car can travel before it would start to slide is approximately 34.305 meters per second.
A certain force gives object m1 an acceleration of 12.0 m/s2. The same force gives object m2 an acceleration of 3.30 m/s2. What acceleration would the force give to an object whose mass is (a) the difference between m1 and m2 and (b) the sum ofm1 andm2
Answer:
a) a = 4,552 m / s², b) a = 2,588 m / s²
Explanation:
Newton's second law is
F = ma
a = F / m
in this case the force remains constant
indicate us
* for a mass m₁
a₁ = F/m₁
a₁ = 12, m/ s²
* for a mass m₂
a₂= 3.3 m / s²
a) acceleration
m = m₂-m₁
we substitute
a = [tex]\frac{F}{m_2 - m_1}[/tex]
1 / a = [tex]\frac{m_2}{F} - \frac{m_1}{F}[/tex]
let's calculate
[tex]\frac{1}{a}[/tex] = [tex]\frac{1}{3.3} - \frac{1}{12}[/tex]
[tex]\frac{1}{a}[/tex] = 0.21969
a = 4,552 m / s²
b) m = m₂ + m₁
a = F / (m₂ + m₁)
[tex]\frac{1}{a} = \frac{m_2}{F} + \frac{m_1}{F}[/tex]
we substitute
[tex]\frac{1}{a} = \frac{1}{3.3} + \frac{1}{12}[/tex]
a = 2,588 m / s²
Which image shows the difference between the speed of molecules in hot and cold water? Explain your answer choice.
HELP ME,EVERYONE!!!!!!!! :(
Answer:
the answer is B
Explanation:
I think its B because on the top it shows the molecule speed and A looks like the water is cold, C shows that the hot
water is cooler, and D shows that both are cold
Which action will leave the dump trucks inertia unchanged?? PLEASE ANSWER FAST!!!
A. add gas
B. increase force applied to engine
Answer:
B.
Explanation:
Introduction: The specific heat capacity of a substance is the amount of energy needed to change the temperature of that substance by 1 °C. Specific heat capacity can be calculated using the following equation:
q = mc deltaT
In the equation q represents the amount of heat energy gained or lost in joules), m is the mass of the substance (in grams), c is the specific heat capacity of the substance (in J/g °C), and AT is the temperature change of the substance in °C).
Goal: Calculate the specific heat capacities of copper, granite, lead, and ice.
Solve: When you mix two substances, the heat gained by one substance is equal to the heat lost by the other substance. Suppose you place 125 g of aluminum in a calorimeter with 1,000 g of water. The water changes temperature by 2 °C and the aluminum changes temperature by -74.95 °C.
A. Water has a known specific heat capacity of 4.184 J/g °C. Use the specific heat equation to find out how much heat energy the water gained (q).
B. Assume that the heat energy gained by the water is equal to the heat energy lost by the aluminum. Use the specific heat equation to solve for the specific heat of aluminum. Aluminum's accepted specific heat value is 0.900 J/g °C. Use this value to check your work.
Answer:
A) 8,368 J
B) ) 0.893 J/gºC
Explanation:
A)
The heat gained by the water can be obtained solving the following equation:[tex]q_{g} = c_{w} * m * \Delta T (1)[/tex]
where cw = specific heat of water = 4.184 J/gºCm= mass of water = 1,000 gΔT = 2ºC Replacing these values in (1) we get:[tex]q_{g} = c_{w} * m * \Delta T = 4.184 J/gºC*1,000 g* 2ºC = 8,368 J (2)[/tex]
B)
Assuming that the heat energy gained by the water is equal to the one lost by the aluminum, we can use the same equation, taking into account that the energy is lost by the aluminum, so the sign is negative: -8,368 J.Replacing by the mass of aluminum (125 g), and the change in temperature (-74.95ºC), in (1), we can solve for the specific heat of aluminum, as follows:[tex]q_{l} = c_{Al} * m_{Al} * \Delta T (3)[/tex]
⇒ [tex]-8,368 J = c_{Al}* 125 g * (-74.95ºC) (4)[/tex]
[tex]c_{Al} = \frac{-8,368J}{125g*(-74.95ºC} = 0.893 J/gºC (5)[/tex]
which is pretty close to the Aluminum's accepted specific heat value of 0.900 J/gºC.
Why is damage from sound waves is an issue on the launchpad but not in the air
(I would have done more points for answering but I'm almost out sry. just pls answer and help.)
The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.
Closeness to the Sound Source: When a rocket is fired on the launchpad, it creates a tremendous amount of noise in proximity to the nearby equipment and structures.
When a rocket is launched, concentrated sound waves are created that can seriously harm neighboring structures, especially if such structures are not built to handle such strong vibrations. In contrast, once a rocket is in the air, the sound waves spread out and become less forceful as they travel through the atmosphere, decreasing the possibility that they may cause harm.
Reflection and Amplification: The launchpad environment can serve as an echo chamber for sound waves because of its huge, solid structures.
Hence, The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.
To learn more about soundwave, here:
https://brainly.com/question/31851162
#SPJ4
PLEASEEEEEEEEE HELPPPPPPPPPP
Describe what determines magnetism.
Answer:
Magnetism is caused by the motion of electric charges. Every substance is made up of tiny units called atoms. Each atom has electrons, particles that carry electric charges. ... Their movement generates an electric current and causes each electron to act like a microscopic magnet.
Explanation:
True or False do Eclipses, tides, season, and moon phases ALL have to do with the positions of the Earth, Sun, and Mars.
Which is the best explanation for why Toms technique works ?
According to Newton’s second law of motion, when an object is acted on by an unbalanced force, how will that object respond?
It will stop moving.
It will accelerate.
It will decrease speed.
It will increase velocity.
It will accelerate. A force of magnitude F exerted on an object of mass m applies an acceleration a according to
F = m a
Remember that force and accleration are vector quantities, so the object's acceleration would point in the same direction as the applied force. The other choices describe some possible outcomes, but
• it the object starts in motion, it can only stop moving if the force opposes the motion and acts in the opposite direction. The object would eventually stop, but only for an instant before changing direction and starting to move again. Consider a ball being thrown directly upward, reaching its highest point, then falling again.
• its speed (which is a scalar quantity) would only decrease if the object starts in motion and is slowed down. But if it starts at rest, its speed can only increase. Consider a ball being dropped from some height and gaining speed as it falls.
• its velocity will certainly change, but can only increase if the object is at rest, or if it's already in motion and the force points in the same direction.
Answer:
It will accelerate.
Explanation:
i go to K12
This problem, a squid at rest suddenly sees a predator coming toward it and needs to escape. Assume the following:______.
(i) Including the water in its internal cavity, the squid has a total mass of 6.50 kg.
(ii) The mass of the water in its cavity is 1.75 kg.
(iii) In order to escape its predators, the squid needs to achieve an escape speed of 2.5 m/s.
Answer:
6.79 m/s
Explanation:
By applying the principle of conservation of momentum.
The total momentum = MV - mv = 0 (since the squid is beginning at rest)
the mass of the squid (M) in absence of water in its cavity = (6.5 - 1.75) kg
= 4.75 kg
speed of the squid (V) = 2.5 m/s
mass of the water expelled (m) = 1.75 kg
speed of the water (v) = ???
∴
4.75 × 2.5 = 1.75 × v
[tex]v = \dfrac{4.75 \times 2.5}{1.75 }[/tex]
v = 6.79 m/s
Chemical messengers that stimulate a specific cellular response.
Glucose
Hormones
Mitochondria
Nerves
Answer:
Explanation:
hormones. please mark me brainliest
If 478 watts of power are used in 14 seconds,how much work was done
Answer:
6692J
Explanation:
Power is defined as the rate at which work is being done.
So,
Power = [tex]\frac{workdone}{time }[/tex]
Work done = Power x time
Given parameters:
Power = 478watts
Time = 14s
So;
Work done = 478 x 14 = 6692J
1. The volume of a given mass of gas is 20cm when its
pressure is 400mmHg. Calculate its pressure when the
volume becomes 80cm'at constant temperature,
Answer:
Explanation:
The way to show a cubed substance is either like this³ or like this x^3. The small three is found at the bottom toolbar at the bottom of the question space marked by the Ω symbol.
100 mmHg
Givens
V1 = 20 cm^3
V2 = 80 cm^3
P1 = 400 mmHg
P2 = ?
Formula
V1 * P1 = V2 * P2
Solution
20 * 400 = 80 * P2 Divide by 80
20 * 400/80 = P2
P2 = 8000 / 80
P2 = 100 mmHg
A 87 kg man has a total mechanical energy of 1780 J .If he is swinging downward and is currently 1.4 m above the ground, what is his speed? Use g = 10 m/s^2
Answer:
6.4m/s
Explanation:
The total mechanical energy of the man is 1780J.
This mechanical energy is the energy due to the motion of the body and it is a form of kinetic energy.
Also, mass = 87kg
Kinetic energy = [tex]\frac{1}{2}[/tex] m v²
m is the mass
v is the velocity
1780 = [tex]\frac{1}{2}[/tex] x 87 x v²
v² = 40.9
v = 6.4m/s
A weightlifter curls a 32 kg bar, raising it each time a distance of 0.50 m. How many times must he repeat this exercise to burn off the energy in one slice of pizza? Assume 25% efficiency.
Answer:
Explanation:
Average energy contained by a slice of pizza is 860 J .
energy used in lifting 32 kg bar by .50 m = mgh
= 32 x 9.8 x .5 = 156.8 J
efficiency is 25 % , so energy used up = .75 x 156.8 = 117.6 J
So number of times exercise to be repeated to burn off energy of a slice of pizza
= 860 / 117.6
= 7.3 or 7 times .
An 88 kg person steps into a car of mass 2002 kg, causing it to sink 5.36 cm on itssprings. Assuming no damping, with what fre-quency will the car and passenger vibrate onthe springs? Answer in units of Hz. The acceleration of gravity is 9.81 m/s^2.
Answer:
The required frequency = 0.442 Hz
Explanation:
Frequency [tex]f = ( \dfrac{1}{2 \pi}) \omega[/tex]
where;
[tex]\omega = \sqrt{\dfrac{k}{m} }[/tex]
Then;
[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{k}{m} } \Bigg )[/tex]
However;
[tex]k = \dfrac{F}{x}[/tex] and;
mass [tex]m = m_{car } + m_{person}[/tex]
[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{\dfrac{F}{x}}{m_{car}+m_{person}} } \Bigg )[/tex]
[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{{F}}{x(m_{car}+m_{person})} } \Bigg )[/tex]
where;
[tex]F = m_{person}g[/tex]
Then;
[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{ {m_{person}g }}{x(m_{car}+m_{person})} } \Bigg )[/tex]
replacing the values;
[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{ {(88 \ kg)* (9.81 \ m/s^2) }}{(5.36 \times 10^{-2} \ m) (2002 \ kg +88 \ kg)} } \Bigg )[/tex]
[tex]\mathbf{f = 0.442 \ Hz}[/tex]
The graph shows projected changes in the populations of the world.
World Population Growth
20,000
10,000
World
5,000
Asia
2,000
Africa
1,000
Europe
500
200
United States,
Canada, and Greenland
100 Mexico
Central America, Caribbean Islands,
50
and South America
Oceania (Australia and
20
nearby islands in the Pacific)
10
2040
2050
Based on the information in the graph, which region is expected to have the
greatest increase in its population over the period shown?
1950
1960
1970
1980
1990
2000
2010
2020
2030
Answer: C. Africa
Explanation:
The data given on the graph shows that:
Asia will grow from around 1,300 million to 5,000 million in 2050 which is an increase of:
= 5,000 /1,300 = 3.84 times
Europe will decrease over that period.
Africa will go from around 300 million to 2,000 million which is an increase of:
= 2,000 / 300
= 6.67 times
Mexico
, Central America, Caribbean Islands:
= 900 / 120
= 7.5 times
United States, Canada, and Greenland:
= 400/120
= 3.33
Oceania:
= 50 / 13
= 3.85
From the options give, Africa will see the greatest increase at 6.67 times its population in 1950.
Explain the relationship between the current output of the power supply and the current through each component in the parallel circuit.
Explanation:
Current output at the battery will be current of entire circuit, while the current through each bulb in the parallel circuit is the total current circuit.
So, current output through power supply is i and current through each component be [tex]i_1, i_2 , i_3[/tex] considering only three component.
Then in a parallel circuit
[tex]i = i_1+i_2+i_3[/tex]
A car is traveling at a constant speed of 20 m/s for 3 seconds. Then the driver puts on the brakes. The total distance the car travels is 100 m. What is the total time the car was moving?
Answer:
15 seconds
Explanation:
If car was moving at 20m/s for 3 sec.
if car traveled 100m = 15 sec total
A hot-air balloon has a volume of 2500 m3 . The balloon fabric (the envelope) weighs 860 N . The basket with gear and full propane tanks weighs 1200 N .
a) If the balloon can barely lift an additional 3400 N of passengers, breakfast, and champagne when the outside air density is 1.23kg/m3, what is the average density of the heated gases in the envelope?
Answer:
1.007 kg/m³
Explanation:
Given that:
volume = 2500 m³
density of air [tex]\rho = 1.23 \ kg/m^3[/tex]
weight of air displaced = [tex]V \times \rho \times g[/tex]
= 2500 × 1.23 × 9.81
= 30165.75 N
weight of the ballon fabric = 860 N; &
The propane weight = 1200 N
The passenger additional weight = 3400 N
weight of the heated gas will be = V × d × g
= 2500 × d 9.81
= 24525 d
For floating
The weight of air displaced is less than 30165.75
∴ 860 + 1200 + 3400 + 24525 d = 30165.75
5460 + 24525 d = 30165.75
24525 d = 24705.75
d = 24705.75 / 24525
d = 1.007 kg/m³
Hence, the average density of the heated gas = 1.007 kg/m³
I WILL GIVE YOU BRAINLIEST! PLEASE HELP
A daydreaming soccer player takes a 0.47 kg ball to the face experiencing an impact force of 1060.9 N. If the ball hit the
player's face with a speed of 14.5 m/s and bounces off in the opposite direction with the same speed, calculate the time of
impact. Note: The time of impact will be a fraction of a second so answer with at least 5 decimal places
Answer:
0.00547s
Explanation:
Step one:
given data
mass= 0.4kg
force= 1060.9N
velocity = 14.5m/s
Frome
Ft= mv
substitute
t= mv/F
t=0.4*14.5/1060.9
t=5.8/1060.9
t=0.00547s
PLZ HELP WILL MARK BRAINLIEST!!
Amy has a mass of 50 kg, and she is riding a skateboard traveling 10 meters per second. What is her momentum?
5 kg·m/s
10 kg·m/s
50 kg·m/s
500 kg·m/s
Answer:
[tex]500 \: \mathrm{kg} \cdot \mathrm{m/s}[/tex]
Explanation:
The momentum of an object is given as [tex]p=mv[/tex]. Since Amy has a mass of 50 kg and is travelling 10 m/s, her momentum is [tex]p=mv=50\cdot 10 =\fbox{$500\: \mathrm{kg\cdot m/s}$}[/tex].
Answer:
500
Explanation:
PLEASEEEEEE HELPPPPPPPPPPP
Describe how a battery works.
Answer:
A battery works because of the electrical energy inside of the battery, which is connected through a wire, which transmits energy through the metal inside of the wire to power to object that the wire is connected to.
Explanation:
Please mark as Brainliest!!!a student lift a 25kg mass at vertical distance of 1.6m in a time of 2.0 seconds. a. Find the force needed to lift the mass (in N ). b. Find the work done by the student (in J). c. Find the power exerted by the student (in W)
Answer:
a. F = 245 Newton.
b. Workdone = 392 Joules.
c. Power = 196 Watts
Explanation:
Given the following data;
Mass = 25kg
Distance = 1.6m
Time = 2secs
a. To find the force needed to lift the mass (in N );
Force = mass * acceleration
We know that acceleration due to gravity is equal to 9.8
F = 25*9.8
F = 245N
b. To find the work done by the student (in J);
Workdone = force * distance
Workdone = 245 * 1.6
Workdone = 392 Joules.
c. To find the power exerted by the student (in W);
Power = workdone/time
Power = 392/2
Power = 196 Watts.
If California experienced heavy rainfall, which system would be responsible for it and WHY?
Answer:
California has one of the most variable climates of any U.S state, and often experiences very wet years followed by extremely dry ones . The state's reservoirs have insufficient capacity to balance the water supply between wet and dry years.
PLEASE MARK ME AS BRAINLIEST
What is the correct organization of living things, from smallest to largest?
Cells - Tissues - Organs - Organ Systems - Organism
Organs - Tissues - Cells - Organ Systems - Organism
Cells - Organs - Tissues - Organism - Organ Systems
Cells - Organism - Tissues - Organ Systems - Organs