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4 years ago

When the polarity of the Sun's magnetic field is taken into account, the solar activity cycle lasts ____.

Physics

1 answer:

Bas_tet [7]4 years ago

8 0

Answer:

10.6 Years

Explanation:

The Sun is a very volatile body. It shows a lot of features like solar flares, sun spots, prominence etc. These features are result of the magnetic field and differential rotation of the Sun. The regarding the no. of sun spots visible, solar flares, intensity of flares etc. have been collected for years and it can be seen that these activities follow a cycle with maxima and minima.

This cycle is of 10.6 years. The change in the solar activity also affects some terrestrial phenomenon such as Aurora.

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Two identical billiard balls are rolling toward each other at the same speed. What will be true after they collide head-on?

tino4ka555 [31]

Answer:

They will both bounce back at the same speed they had before the collision

Explanation:

Assuming an elastic collision, kinetic energy will be conserved. Therefore, the billiard balls will have the same speed after the collision as before the collision.

7 0

3 years ago

A person walks at a speed of 6 km/h from point A to point B. If he improves his pace by 1.5 km/h, he will arrive 1 hour earlier.

Fofino [41]

Answer:

a) The distance is 30 km

The time duration is 5 hours

b) s₁ is approximately 28.142 km or s₁ is approximately 1.505 km

Explanation:

The initial speed with of the person, v₁ = 6 km/h

The distance the walked by the person, d = From point A to point B

The rate at which the person increases the speed, Δv = 1.5 km/h

The time it takes for the person to arrive at point B from point A at the new speed, t₂ = 1 hour earlier than when walking at 6 km/h

a) Let t₁ represent the time it takes the person walking from point A to point B at 6 km/h, we have;

t₂ = t₁ - 1...(1)

d/t₁ = 6...(2)

d/t₂ = 6 + 1.5 = 7.5

∴ d/t₂ = 7.5...(3)

From equation (2), we have;

d = 6 × t₁ = 6·t₁

Plugging in d = 6·t₁, and t₂ = t₁ - 1 in equation (3) gives;

d/t₂ = 7.5

∴ 6·t₁/t₁ - 1 = 7.5

6·t₁ = 7.5 × (t₁ - 1) = 7.5·t₁ - 7.5

7.5·t₁ - 6·t₁ = 7.5

1.5·t₁ = 7.5

t₁ = 7.5/1.5 = 5

t₁ = 5

The time it takes the person walking from point A to point B at 6 km/h, t₁ = 5 hours

The distance from point A to point B, d = 6 km/h × 5 hours = 30 km

b) The distance the person travels at the initial speed, v₁ (6 km/h) = s₁

The duration the person pauses for a rest = 15 minutes = 1/4 hours

The speed with which he walks the rest of the journey, v₂ = 7.5 km/h

The time earlier than expected that he arrives, Δt = 30 minutes = 0.5 hours

We note that the total distance, d = 30 km

The expected time, t₁ = 5 hours

Therefore, we have;

s₁ + s₂ = 30 km

s₂ = 30 - s₁

v₁/s₁ + 1/4 + v₂/s₂ = t₁ - 0.5

Therefore;

6/s₁ + 1/4 + 7.5/(30 - s₁) = 5 - 0.5 = 4.5

6/28.142+ 1/4 + 7.5/(30 - 28.142) = 5 - 0.5 = 4.5

6/s₁ + 7.5/(30 - s₁) = 4.5 - 1/4 = 4.25

-(3·s₁ + 360)/(2·s₁²- 60·s₁) = 4.25

2·s₁²- 60·s₁) × 4.25 + 3·s₁ + 360 = 0

17·s₁²- 504·s₁ + 720 = 0

s₁ = (504 ± √((-504)² - 4 × 17 × 720))/(2 × 17)

s₁ ≈ 28.142 or s₁ = 1.505

The distance the individual travels at v₁ = 6 km/h, s₁ ≈ 28.142 km or 1.505 km

4 0

3 years ago

An object moves with simple harmonic motion. If the amplitude and the period are both doubled, the object's maximum speed is 1.

Kisachek [45]

Answer:

The object's maximum speed remains unchanged.

Explanation:

The speed of a particle in SHM is given by :

$v(t)=A\omega\ sin(\omega t)$

Maximum speed is, $v_{max}=A\omega$

If A' = 2A and T' = 2T

$v'_{max}=(2A)\dfrac{2\pi}{2T}$

$v'_{max}=(A)\dfrac{2\pi}{T}$

$v'_{max}=v_{max}$

So, the maximum speed of the object remains the same i.e. it remains unchanged. Hence, this is the required solution.

6 0

3 years ago

Factor each expression.<br>a. d2 + 8d + 7

Y_Kistochka [10]

Answer:

the answer is (d + 1) (d + 7)

8 0

3 years ago

a 645 N person is wearing stiletto shoes. If she lifts her left leg, and rocks back onto the heel under her right leg, the press

fgiga [73]

Answer:

0.96cm

Explanation:

Given parameters:

Weight of person = 645N

Pressure of the heel = 9000000PA

Unknown

Diameter of the circular base = ?

Solution

Pressure is the force per unit area of a body.

Pressure = $\frac{Force}{Area}$

To solve this problem, find the unknown area of the circle;

Pressure x Area = Force

Area = $\frac{Force}{Pressure}$

Area = $\frac{645}{9000000}$ = 7.17 x 10⁻⁵m²

Note: 1Pa = 1Nm⁻²

Now;

Area of a circle = π r²

r = $\frac{d}{2}$

Area = π x $\frac{d^{2} }{4}$

d is the diameter

d² = 4 x Area x (1/π)

d² = 4 x 7.17 x 10⁻⁵ x (1/3.14) = 9.13 x 10⁻⁵

d = 0.0096m

To cm;

100cm = 1m

0.0096m; 0.0096 x 100= 0.96cm

7 0

3 years ago