Answer:
Newton's law of cooling states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings. The law is frequently qualified to include the condition that the temperature difference is small and the nature of heat transfer mechanism remains the same. As such, it is equivalent to a statement that the heat transfer coefficient, which mediates between heat losses and temperature differences, is a constant. This condition is generally met in heat conduction (where it is guaranteed by Fourier's law) as the thermal conductivity of most materials is only weakly dependent on temperature. In convective heat transfer, Newton's Law is followed for forced air or pumped fluid cooling, where the properties of the fluid do not vary strongly with temperature, but it is only approximately true for buoyancy-driven convection, where the velocity of the flow increases with temperature difference. Finally, in the case of heat transfer by thermal radiation, Newton's law of cooling holds only for very small temperature differences.
When stated in terms of temperature differences, Newton's law (with several further simplifying assumptions, such as a low Biot number and a temperature-independent heat capacity) results in a simple differential equation expressing temperature-difference as a function of time. The solution to that equation describes an exponential decrease of temperature-difference over time. This characteristic decay of the temperature-difference is also associated with Newton's law of cooling
A girl of weight 500 N climbs on top of a 2.0 m high wall. By how much does her g.p.a increase?
Answer:
By 1000 joules
Explanation:
Given
[tex]Weight = 500N[/tex]
[tex]Height = 2.0m[/tex]
Required
By how much does her GPA increases
To do this, we simply calculate the potential energy.
[tex]GPE = mgh[/tex]
Where
[tex]mg = Weight = 500N[/tex]
At the ground level, the height is 0
i.e. [tex]h = 0[/tex]
So:
[tex]GPE = 500N * 0 = 0[/tex]
At:
[tex]h = Height = 2.0m[/tex]
So, we have:
[tex]GPE = mgh[/tex]
[tex]GPE = 500N * 2.0m[/tex]
[tex]GPE = 1000J[/tex]
Calculate the difference
[tex]\triangle GPE = 1000J - 0J[/tex]
[tex]\triangle GPE = 1000J[/tex]
Hence, it increases by 1000 joules
Particles q1 = +8.0 UC, 92 = +3.5 uc, and
q3 = -2.5 uC are in a line. Particles qi and q2 are
separated by 0.10 m and particles q2 and q3 are
separated by 0.15 m. What is the net force on
particle q2?
Answer:
-22.3
Explanation:
Acellus
The net force on particle q2 is 21.7 N.
The given parameters:
Charge on particle 1, q1 = 8 μCCharge on particle 2, q2 = 3.5 μCCharge on particle 3, q3 = -2.5 μCDistance between particle 1 and particle 2 = 0.1 mDistance between particle 2 and particle 3, = 0.15 mThe net force on particle q2 is calculated as follows;
[tex]Q_2_{net} = q_{12} \ + \ q_{23}\\\\Q_2_{net} = \frac{kq_1q_2}{r_{12} ^2} \ + \ \frac{kq_2q_3}{r_{23}^2} \\\\Q_2_{net} = \frac{9\times 10^9 \times 8 \times 10^{-6} \times 3.5 \times 10^{-6} }{0.1^2} \ + \ \frac{9 \times 10^9 b\times 3.5 \times 10^{-6} \times (-2.5) \times 10^{-6} }{0.15^2} \\\\Q_2_{net} = 25.2 \ N \ - \ 3.5 \ N\\\\Q_2_{net} = 21.7 \ N[/tex]
Thus, the net force on particle q2 is 21.7 N.
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Acceleration is rate of change of
A-Position
B-Time
C-Velocity
D-Speed
Question /
Which object is shown below?
A. Convex mirror
B. Convex lens
C. Concave lens
D. Concave mirror
SLIDNAT
Which of the following questions could you ask if you wanted to expand on the following piece of data?
Standardized testing helps hold schools and teachers accountable for students' performance.
A. Are there any negative effects associated with standardized testing?
B. How effective are the tests at assessing whether a student has learned a particular skill?
C. Who decides what should be included in a standardized test?
D. All of the above are correct.
My best friend just returned from the clinic. She just found out she is HIV- positive. She invited me for dinner. What should I do? Should I go? What do I say to her and her family? Can I eat the foods she cooked or touched? Will she be all right? Imagine this letter is from a friend. Write a page response. Include reasons for your advice.
Answer:
yes, because you dont want to be mean and make her feel worse about it and hiv has something do with s3x not germs so yes go
Explanation:
A 1,571 kilogram car travelling at 129 kilometers per hour is driving down a highway. The driver suddenly realizes a large animal is standing stationary on the highway in the way of the car. The driver manages to release their foot off the accelerator peddle, but does not have time to hit the brake peddle. The car strikes the animal which gets stuck to the car hood. Immediately after the collision the car slows to 59 kilometers per hour. Given this information, accident investigators are able to determine the mass of the animal as what
Answer:
[tex]1863.9\ \text{kg}[/tex]
Explanation:
[tex]m_1[/tex] = Mass of car = 1571 kg
[tex]u_1[/tex] = Initial velocity of car = 129 km/h
[tex]u_2[/tex] = Initial velocity of the animal = 0
[tex]v[/tex] = Velocity of combined mass = 59 km/h
[tex]m_2[/tex] = Mass of the animal
As the momentum of the system is conserved we have
[tex]m_1u_1+m_2u_2=(m_1+m_2)v\\\Rightarrow \dfrac{m_1u_1+m_2u_2}{v}-m_1=m_2\\\Rightarrow m_2=\dfrac{1571\times 129+0}{59}-1571\\\Rightarrow m_2=1863.9\ \text{kg}[/tex]
The mass of the animal is [tex]1863.9\ \text{kg}[/tex].
When putting the ball on the tee you want half of the golf ball to be above the club be below the club be in front of the club be behind the club
will put brainlest
A golf ball is a unique ball made specifically for the game of golf.
What is Gulf ball?A golf ball must adhere to specific velocity, distance, and symmetry requirements as well as have a mass of no more than 1.620 oz (45.9 g), a diameter of no less than 1.680 inches (42.7 mm), and no more than 1.620 oz (45.9 g) in total.
Similar to golf clubs, golf balls must pass testing and approval by The R&A and the United States Golf Association before they can be used in competitions.
Early in the 20th century, it was discovered that dotting the ball gave the player even more control over the trajectory, flight, and spin of the ball.
Therefore, A golf ball is a unique ball made specifically for the game of golf.
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Which statement explains why a blue car does not appear to be red?
A. Blue light is absorbed by the car.
B. Red light is absorbed by the car.
C. Blue light is transmitted through the car.
D. Red light is transmitted through the car.
Answer: B. Red light is absorbed by the car.
Explanation:
The colour of the object is decided by the wavelength of light that it reflects.
Light with the longest wavelength appears red, and light with the shortest wavelength appears violet. The wavelengths of visible light that an object reflects or transmits determine the color that the object appears to the human eye.
The blue car appears blue as it absorbs red light and reflects blue colour.
In 1960, the US Navy sent the submersible Trieste to the bottom of the Marianas Trench 11,000m deep. What was the force on the small 15cm diameter circular viewing window?
Answer:
P = d g h pressure = density * g * depth
P = 1000 kg/m^3 * 9.8 m / s^2 * 1.1 * 10E4 m = 1.1 * 10E8 N/m^2
F = P * A = 1.1 * 10E8 N/m^2 * pi * .075^2 / m^2 = 1.9 * 10E6 N/m^2
5. What is the period of a vertical mass-spring system that has an amplitude of
71.3 cm and maximum speed of 7.02 m/s? The spring constant is 12.07 N/m.
The period of the vertical mass-spring is 0.64 s.
The given parameters:Amplitude of the spring, A = 71.3 cm Maximum speed of the spring, V = 7.02 m/sSpring constant, k = 12.07 N/mThe angular speed of the vertical mass-spring is calculated as follows;
[tex]V_{max} = A \omega\\\\\omega = \frac{V_{max}}{A} \\\\\omega = \frac{7.02}{0.713} \\\\\omega = 9.85 \ rad/s[/tex]
The period of the vertical mass-spring is calculated as follows;
[tex]f = \frac{\omega }{2\pi} \\\\T = \frac{1}{f} \\\\T = \frac{2 \pi}{\omega } \\\\T = \frac{2\pi }{9.85} \\\\T = 0.64 \ s[/tex]
Thus, the period of the vertical mass-spring is 0.64 s.
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how is the medium of a wave and transmit of a wave similar and different?
plssss I really need helpppp
Answer:
Sound and light are similar in that both are forms of energy that travel in waves. They both have properties of wavelength, freqency and amplitude. Here are some differences: Sound can only travel through a medium (substance) while light can travel through empty space.
Help answer question in picture
Please help me with 1&2
Answer:
1: A
Explanation:
please help in this question!! I will mark brainlest
Answer:
im not too sure about that all i know is history
An SUV has a mass of 6000 kg and a compact car has a mass of 2000 kg. They both go around the same unbanked circular curve on the freeway. Bumper to bumper they go with the same speed vo. The centripetal acceleration of the compact car is ao and the centripetal force acting is Fo. The centripetal acceleration of the SUV is _____ ao of the compact car.
Answer:
Therefore, the centripetal acceleration of the SUV is 3 times ao of the compact car.
Explanation:
FOR SUV:
[tex]ac_{suv} = \frac{mv^2}{r}\\[/tex]
where,
ac_suv = centripetal acceleration of the SUV = ?
m = mass of SUV = 6000 kg
v = speed of SUV = vo
r = radius of path
Therefore,
[tex]ac_{suv} = \frac{6000\ vo^2}{r}\\[/tex]---------------- equation (1)
FOR CAR:
[tex]ao = \frac{mv^2}{r}\\[/tex]
where,
ao = centripetal acceleration of the car = ?
m = mass of car = 2000 kg
v = speed of car = vo
r = radius of path
Therefore,
[tex]ao = \frac{2000\ vo^2}{r}\\[/tex]--------------------- equation (2)
Dividing equation (1) by eq(2):
[tex]\frac{ac_{suv}}{ao} = \frac{6000}{2000}\\\\ac_{surv} = 3ao[/tex]
Therefore, the centripetal acceleration of the SUV is 3 times ao of the compact car.
help pls thx!!!!!!!
this is my last question i hope!
Answer:
Left
Explanation:
newtons is a measure of force. Since there is more newtons(force) pushing to the left, the object will move left. the 15 newtons cancel each other out, leaving only 5 newtons pushing to one side with no resistance.
In Figure (a), both batteries have em - 1.20 V and the external resistance R is a variable resistor. Figure (6) gives the electric potentials V between the terminals of each battery as functions of
Curve 1 corresponds to battery 1, and curve 2 corresponds to battery 2. The horizontal scale is set by R, -0.500 . What is the internal resistance of (a) battery 1 and (b) battery 2?
0.60
V(V)
0
-0.350
(
R(0)
(6)
Answer:
i know da way ese'
Explanation:
The 360-turn primary coil of a step-down transformer is connected to an ac line that is 120 V (rms). The secondary coil is to supply 15.0 A at 6.30 V (rms). 1) Assuming no power loss in the transformer, calculate the number of turns in the secondary coil. (Express your answer to two significant figures.)
Answer:
N₂ = 19 turns
Explanation:
A transform is a system with two different windings where the variation of the magnetic beam is the same, if there are no losses in the system we can use Faraday's law
V₁ = -N₁ [tex]\frac{d \Phi_B }{dt}[/tex]
v₂ = - N₂ \frac{d \Phi_B }{dt}
[tex]\frac{V_1}{N_1} = \frac{V_2}{N_2}[/tex]
in this case we look for the number of turns in the second winding
N₂2 = [tex]N_1 \ \frac{ V_2}{V_1}[/tex]
calculate us
N₂ = 360 6.30/ 120
N₂ = 18.9 turn
The number of turns must be an integer
N₂ = 19 turns
8.
A
2.0 m
A 1.0 kg box slides without friction around the
loop-the-loop apparatus as shown in the
diagram. If the object starts from rest at point A,
and the radius of the loop is 0.75 m, what is the
speed of the box at point B?
Answer:
6.26 m/s
Explanation:
From the given information:
Using the conservation of Energy;
M.E at A =M.E at B
[tex]\dfrac{1}{2}mv_A^2 + mgh _A = \dfrac{1}{2}mv_B^2 + mgh_B[/tex]
Replacing the values given in the equation:
[tex](1) (9.8) (2 \ m) +\dfrac{1}{2}(0)^2 = 1 \times 9.8 \times 0 + \dfrac{1}{2}(1) \times v_B^2 \\\\ 19.6 + 0 = 0 + 0.5v_B^2\\ \\ v_B^2 = \dfrac{19.6}{0.5} \\ \\ v_B^2 = 39,2 \\ \\ v_B = \sqrt{39.2} \\ \\ \mathbf{v_B = 6.26 \ m/s}[/tex]
4. Which of the following accurately pairs the part of an atom to its charge?
O A. Neutron-positive charge
O B. Electron-negative charge
O C. Proton-no charge
O D. Electron-no charge
Answer:
B Electrons are negatively charged while protons are positively charged
Which sentence best explains the law of conservation of mass as applied to
chemical reactions?
A. The amount of mass changes only slightly during a chemical
reaction.
B. The volumes of the reactants and products are equal during a
chemical reaction.
C. The types of atoms can change during a chemical reaction, but
their masses cannot.
D. In a chemical reaction, the total mass of the reactants equals the
total mass of the products.
Answer:
A. The amount of mass changes only slightly during a chemical
reaction.
The diagram represents two charges, q1 and q2 separated by a distanced "d" which change would produce the greatest increase in the electrical force between the two charges?
between the two charges?
Answer:
The diagram represents two charges, q1 and q2, separated by a distance d. Which change would produce the greatest increase in the electrical force between the two charges? *
Explanation:
doubling charge q1, only
Doubling the charge q would produce the greatest increase in the electrical force between the two charges.
The value of the electrostatic force of interaction between two point charges is directly proportional to the scalar multiplication of the charges and inversely proportional to the square of the distance between them.
How would you define an Electrical force?
The repulsive or attractive interaction between any two charged bodies is called as an electric force. Similar to any force, its impact and effects on the given body are described by Newton’s laws of motion. The electric force is among the list of other forces that exert over objects.
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Ac soucre change it polarity how many time
Why is it that when riding in a car, you don't feel like you're moving?
This may shock you:
We NEVER feel speed, velocity, or motion, as long as it's constant.
We only feel CHANGES in speed, velocity, or motion.
That means speeding up, slowing down, or changing direction.
As long as we're moving in a straight line at a constant speed, we don't feel anything.
Light with a wavelength of 600 nm shines onto a single slit, and the diffraction pattern is observed on a screen 2.5 m away from the slit. The distance, on the screen, between the dark spots to either side of the central maximum in the pattern is 25 mm. (a) What is the distance between the same dark spots when the screen is moved so it is only 1.5 m from the slit
Answer:
"6.67 mm" is the right solution.
Explanation:
The given values are:
L = 2.5 my = .0125λ = 600 nmAs we know, the equation
⇒ [tex]\frac{y}{L} =\frac{x \lambda}{a}[/tex]
On substituting the values, we get
⇒ [tex]\frac{.0125}{2.5}=\frac{(1)(600\times 10^{-9}) }{a}[/tex]
On applying cross multiplication, we get
⇒ [tex].0125a=2.5 (600\times 10^{-9})[/tex]
⇒ [tex]a=\frac{2.5(600\times 10^{-9})}{.0125}[/tex]
⇒ [tex]=1.2\times 10^{-4} \ m[/tex]
For new distance, we have to put this value of "a" in the above equation,
⇒ [tex]\frac{y}{1.5} =\frac{(1)(600\times 10^{-9})}{1.2\times 10^{-4}}[/tex]
⇒ [tex](1.2\times 10^{-4})y=1.5(600\times 10^{-9})[/tex]
⇒ [tex]y=\frac{1.5(600\times 10^{-9})}{1.2\times 10^{-4}}[/tex]
⇒ [tex]=3.22\times 10^{-3} \ m[/tex]
The total distance will be twice the value of "y", we get
= [tex]6.67\times 10^{-3} \ m[/tex]
or,
= [tex]6.67 \ mm[/tex]
A man stands by a railway track.
A train travelling at 40 m/s takes 2.0 s to pass the man.
What is the length of the train?
40 m
D
80m
A 20m
B 38 m
Answer:
length of train is 80m
Explanation:
40*2
If a force of 20kN acts on a circular rod of diameter 10mm, calculate the stress in the
rod.
The stress in the rod is equal to [tex]2.55 \times 10^8\;N/m[/tex]
Given the following data:
Force = 20 kN = 20,000 NewtonDiameter = 10 mm to m = 0.01 meterTo calculate the stress in the rod:
First of all, we would determine the area of the rod by using this formula:
[tex]Area = \frac{\pi d^2}{4} \\\\Area = \frac{3.142 \times 0.01^2}{4}[/tex]
Area = 0.00007855 meter.
Mathematically, stress is given by this formula:
[tex]Stress = \frac{Force}{Area}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Stress = \frac{20000}{0.00007855} \\\\Stress = 2.55 \times 10^8\;N/m[/tex]
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Positioning a iron core in the middle of a current carrying solenoid creates:
a. A dipole
b. An electromagnet
c. Induced current
d. Mutual inductance
e. A natural magnet
Answer:
d
Explanation:
middle of a current carrying solenoid creates Mutual inductance
What is the similarity between pushing and lifting? What is the difference?
Answer:
the similarity is that hands are applied and force
