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2 years ago

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The steps in the heating of a metal seat in a park are listed below: Step 1: Heat travels from the sun to Earth Step 2: Heat tra

vels through atmosphere to the top of the seat Step 3: Heat from the top of the seat travels through the seat to the lower parts of the seat Which statement is correct? A. Heat is transferred by radiation in Step 1 and Step 3. B. Heat is transferred by radiation in Step 1 and Step 2.C. Heat is transferred by convection in Step 1 and Step 2. D. Heat is transferred by convection in Step 1 and Step 3.

2 answers:

Shalnov [3]2 years ago

8 0

Answer:

B. Heat is transferred by radiation

I am Lyosha [343]2 years ago

3 0

The steps in the heating of a metal seat in a park are:

Step 1: Heat travels from the sun to Earth

Step 2: Heat travels through atmosphere to the top of the seat

Step 3: Heat from the top of the seat travels through the seat to the lower parts of the seat.

-- Heat is transferred by radiation in Step 1 and Step 2. <em>(B)</em>

-- From the top of the seat to the bottom, heat is transferred by conduction.

There's no convection happening anywhere in the park-hot-seat scenario.

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Vector A with arrow, which is directed along an x axis, is to be added to vector B with arrow, which has a magnitude of 5.5 m. T

ohaa [14]

Answer:

Magnitude of vector A = 0.904

Explanation:

Vector A , which is directed along an x axis, that is

$\vec{A}=x_A\hat{i}$

Vector B , which has a magnitude of 5.5 m

$\vec{B}=x_B\hat{i}+y_B\hat{j}$

$\sqrt{x_{B}^{2}+y_{B}^{2}}=5.5\\\\x_{B}^{2}+y_{B}^{2}=30.25$

The sum is a third vector that is directed along the y axis, with a magnitude that is 6.0 times that of vector A $\vec{A}+\vec{B}=6x_A\hat{j}\\\\x_A\hat{i}+x_B\hat{i}+y_B\hat{j}=6x_A\hat{j}$

Comparing we will get

$x_A=-x_B\\\\y_B=6x_A$

Substituting in $x_{B}^{2}+y_{B}^{2}=30.25$

$\left (-x_{A} \right )^{2}+\left (6x_{A} \right )^{2}=30.25\\\\37x_{A}^2=30.25\\\\x_{A}=0.904$

So we have

$\vec{A}=0.904\hat{i}$

Magnitude of vector A = 0.904

8 0

3 years ago

Assuming that the circuit is in the steady state, what is the total energy stored in the two capacitors? j

Neporo4naja [7]

<span>The total energy stored is the sum of the energy stored in the capacitors. If the capacitors are series connected capacitors, then the charging current is the same for both capacitors. This means that each capacitor stores the same energy and the stored energy is two times the energy of any of the capacitors.</span>

8 0

3 years ago

A 15 kg bucket of water is suspended by a very light ropewrapped around a solid uniform cylinder 0.300 m in diamter withmass 12.

matrenka [14]

Answer:

Part a)

$T = 42 N$

Part b)

$v_f = 11.8 m/s$

Part c)

$t = 1.7 s$

Part d)

$F = 159.7 N$

Explanation:

Part a)

While bucket is falling downwards we have force equation of the bucket given as

$mg - T = ma$

for uniform cylinder we will have

$TR = I\alpha$

so we have

$T = \frac{1}{2}MR^2(\frac{a}{R^2})$

$T = \frac{1}{2}Ma$

now we have

$mg = (\frac{M}{2} + m)a$

$a = \frac{mg}{(\frac{M}{2} + m)}$

$a = \frac{15 \times 9.81}{(6 + 15)}$

$a = 7 m/s^2$

now we have

$T = \frac{12 \times 7}{2}$

$T = 42 N$

Part b)

speed of the bucket can be found using kinematics

so we have

$v_f^2 - v_i^2 = 2 a d$

$v_f^2 - 0 = 2(7)(10)$

$v_f = 11.8 m/s$

Part c)

now in order to find the time of fall we can use another equation

$v_f - v_i = at$

$11.8 - 0 = 7 t$

$t = 1.7 s$

Part d)

as we know that cylinder is at rest and not moving downwards

so here we can use force balance

$F = T + Mg$

$F = 42 + (12 \times 9.81)$

$F = 159.7 N$

5 0

3 years ago

A child (approximately 4 years old) takes her metal “slinky Toy” (a flexible coiled metal spring) and does various tests to dete

anzhelika [568]

Answer:

248

Explanation:

L = Inductance of the slinky = 130 μH = 130 x 10⁻⁶ H

$l$ = length of the slinky = 3 m

N = number of turns in the slinky

r = radius of slinky = 4 cm = 0.04 m

Area of slinky is given as

A = πr²

A = (3.14) (0.04)²

A = 0.005024 m²

Inductance is given as

$L = \frac{\mu _{o}N^{2}A}{l}$

$130\times 10^{-6} = \frac{(12.56\times 10^{-7})N^{2}(0.005024)}{3}$

N = 248

8 0

2 years ago

katen-ka-za [31]

Answer:

True

Explanation:

When an object is held higher, it has more potential energy because more energy is stored from its higher position to swing further than it would have, had it been held lower.

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3 years ago

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