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3 years ago

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A man is walking while riding a train. He says he is moving at 2 mph. A woman standing on a platform at a train station says the

man on the train is moving at 72 mph. Which person is correct?

1 answer:

Semenov [28]3 years ago

6 0

The woman on the platform is correct because it is the pace of the man moving on the train not walking.

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A 22 µF capacitor charged to 0.7 kV and a second 115 µF capacitor charged to 5.5 kV are connected to each other, with the positi

vesna_86 [32]

Answer:

0.099C

Explanation:

First, we need to get the common potential voltage using the formula

$V=\frac {C_2V_2-C_1V_1}{C_1+C_2}$

Where V is the common voltage, C and V represent capacitance and charge respectively. Subscripts 1 and 2 to represent the the first and second respectively. Substituting the above with the following given values then

$C_1=22\times 10^{-6} F\\ C_2=115\times 10^{-6} F\\ V_1= 0.7\times 10^{3}\\V_2=5.5\times 10^{3}$

Therefore

$V=\frac {115\times 10^{-6}\times 5.5\times 10^{3}-22\times 10^{6}\times 0.7\times 10^{3}}{22\times 10^{-6}+115\times 10^{-6}}=4504.3795620437$

Charge, Q is given by CV hence for the first capacitor charge will be $Q_1=C_1V$

Here, $Q_1=22\times 10^{-6}\times 4504.3795620437=0.0990963503649C\approx 0.099C$

8 0

3 years ago

2. A carpenter tosses a shingle off a 9.4 m high roof, giving it an initial horizontal

Aleksandr [31]

Sounds like the shingle/ball is thrown from the roof horizontally, so that the distance it travels <em>x</em> after time <em>t</em> horizontally is

<em>x</em> = (7.2 m/s) <em>t</em>

The object's height <em>y</em> at time <em>t</em> is

<em>y</em> = 9.4 m - 1/2 <em>gt</em>²

where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity, and its vertical velocity is

<em>v</em> = -<em>gt</em>

(a) The object hits the ground when <em>y</em> = 0:

0 = 9.4 m - 1/2 <em>gt</em>²

<em>t</em>² = 2 * (9.4 m) / (9.80 m/s²)

<em>t</em> ≈ 1.92 s

at which time the object's vertical velocity is

<em>v</em> = -<em>g</em> (1.92 s) = -18.8 m/s ≈ -19 m/s

(b) See part (a); it takes the object about 1.9 s to reach the ground.

(c) The object travels a horizontal distance of

<em>x</em> = (7.2 m/s) * (1.92 s) ≈ 13.8 m ≈ 14 m

8 0

3 years ago

What is angular velocity

butalik [34]

Answer:

angular velocity(ω) is the rate change of angular displacement.

ω=θ/t and it SI unit is rad/s

Explanation:

this is very similar with the definition of linear velocity (rate of change of displacement). it specifies the angular speed of an object and the axis about which the object is rotating.

7 0

2 years ago

A certain superconducting magnet in the form of a solenoid of length 0.56 m can generate a magnetic field of 6.5 T in its core w

Gnom [1K]

Answer:

The value is $N =36203 \ turns$

Explanation:

From the question we are told that

The length of the solenoid is $l = 0.56 \ m$

The magnetic field is $B = 6.5 \ T$

The current is $I = 80 \ A$

The desired temperature is $T = 4.2 \ K$

Generally the magnetic field is mathematically represented as

$B = \frac{\mu_o * N * I }{L }$

=> $N = \frac{B * L }{\mu_o * I }$

Here $\mu_o$ is the permeability of free space with value

$\mu_o = 4\pi * 10^{-7} N/A^2$

So

$N = \frac{6.5 * 0.56 }{ 4\pi * 10^{-7} * 80 }$

=> $N =36203 \ turns$

6 0

2 years ago

GIVING BRAINIEST TO FAST ANSWER!!!!

Vlad [161]

Answer:

The second one a part of it heats up Earth's land and water equally.

Explanation:

Hope this help!!!

4 0

2 years ago

Read 2 more answers