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nadya68 [22]
3 years ago
8

A 706-N man stands in the middle of a frozen pond of radius 8.0 m. He is unable to get to the other side because of a lack of fr

iction between his shoes and the ice. To overcome this difficulty, he throws his 1.2-kg physics textbook horizontally toward the north shore at a speed of 8.0 m/s. How long does it take him to reach the south shore?
Physics
1 answer:
mariarad [96]3 years ago
8 0

Answer:

t=62 s

Explanation:

Applying the conservation of linear momentum formula:

(m1+m2)*v_{o1}=m1*v_{f1}+m2*v_{f2}

the initial velocity is zero, we can calculate the man's mass using the gravitational force formula:

F_g=m.g\\\\m=\frac{706N}{9.81}\\\\m=72.0kg

now:

m*v_{f1}=-m_b*v_b\\\\V_{f1}=-\frac{m_b*v_b}{m}\\\\V_{f1}=-\frac{1.2kg*8.0m/s}{72.0kg}\\\\V_f=-0.13m/s

That is 0.13m/s due south.

because there is no friction, the man will maintain a constant velocity, so:

d=v*t\\t=\frac{d}{v}\\t=\frac{8m}{0.13m/s}\\\\t=62s

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IgorC [24]

Answer:

B = \mu_0(\frac{1}{3} \frac{J_0}{r_0} r^2)

Explanation:

As the current density is given as

J = \frac{J_0}{r_0}r

now we have current inside wire given as

i = \int J(2\pi r)dr

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i = \frac{2}{3} \pi \frac{J_0}{r_0} r^3

Now by Ampere's law we will have

\int B. dl = \mu_0 i

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B = \mu_0(\frac{1}{3} \frac{J_0}{r_0} r^2)

4 0
3 years ago
Different between group IA and IIA elements​
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Answer:

Group IA elements have only one valency electron while Group IIA have two valency electrons.

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A 69 kg zebra is traveling 7 m/s east. What is the zebra’s momentum? kg-m/s
Hitman42 [59]
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69\times 7 = 483 kg\cdot m/s
6 0
3 years ago
Help
Blizzard [7]
We can approach this in another way.
We know that sin(∅) = height / hypotenuse.

Thus, for x, height is 1 and hypotenuse is 3. Using Pythagoras theorem,
3² = 1² + b²
b = √8
cos(x) = b/hypotenuse
cos(x) = √8 / 3

Now, lets consider y:
sec(y) = 1 / cos(y) = 1 / base / hypotenuse = hypotenuse / base
The hypotenuse is 25 and the base is 24. We again apply Pythagoras theorem to find the third side, which works out to be:
height = 7
sin(y) = height / hypotenuse
sin(y) = 7/25

Now, sin(x + y) =
sin(x)cos(y) + sin(y)cos(x)
= (1/3)(24/25) + (√8 / 3)(7/25)
= 8/25 + 7√8/75
= (24 + 14√2) / 75
6 0
3 years ago
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When four people with a combined mass of 320 kg
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Each person is 80kg. 320/4
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