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3 years ago

1.) What things signal the coming of spring?

Physics

1 answer:

olasank [31]3 years ago

7 0

Answer:

In Explanation

Explanation:

The signs of the coming of spring include firstly the sight of Robins. It is believed that the sight and singing of the Robins is considered arrival of spring by many in the US. Secondly, the winter is not yet over but the blooming of Daffodils first of all flowers is indication of the spring. As the air gets warmer the flowers bud and new leaves start growing on trees since the days also begin to get longer providing much warmth which also an indicator of the spring.
Without the axial tilt of our Earth, firstly, the Sun would have remained above the equator (Equinox) forever but fortunately due to the tilt we get equinoxes twice a year and not forever. Moreover, the temperature and precipitation levels would not vary much and the equator would remain always warm and the poles always cold. Secondly, due to the tilt as the Earth orbits around the Sun and with changes in solstices we get variety of the seasons which would have been impossible otherwise.

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5. The volume of physical activity attained by an individual who exercises at a level of 7 METs for 35 min · day-1, 4 days · wk-

Airida [17]

D. 980, this is the best answer because 35 x 7 is 980 :)

3 0

3 years ago

A rectangular tank is filled to a depth of 10m with freshwater and open to air at atmospheric pressure.

charle [14.2K]

Answer:

1. 39068.07 N

2. 19534.036 N

Explanation:

depth of water h = 10 m

atmospheric pressure Patm = 101325 Pa

density of water p = 1000 kg/m^3

acceleration due to gravity g = 9.81 m/s^2

pressure due to depth of water = pgh

P = 1000 x 9.81 x 10 = 98100 Pa

total pressure on the bottom of the tank is Patm + p = 101325 + 98100 = 199425 Pa

Left plug has diameter = 50 cm = 0.5 m

radius = 0.5/2 = 0.25 m

height = 1 cm = 0.01 m

height below tank surface = 10 - 0.01 = 9.99

pressure at this depth = 1000 x 9.81 x 9.99 = 98001.9 Pa

total pressure = Patm + P = 101325 + 98001.9 = 199326.9 Pa

surface area of plug = π $r^{2}$ = 3.142 x $0.25^{2}$ = 0.196 $m^{2}$

force required to lift left plug = pressure x area

F = 199326.9 x 0.196 = 39068.07 N

The right side is a hemisphere with the same diameter, therefore surface area is half of the left plug

A = 0.196/2 = 0.098 $m^{2}$

force F required to lift right plug = 199326.9 x 0.098 = 19534.036 N

6 0

3 years ago

Magnesium chloride forms crystals. Which option is a description of this

shtirl [24]

The answer is B. This form of magnesium chloride is not a liquid but a solid that is white and colorless.

4 0

3 years ago

Read 2 more answers

0/2 File Limit

slamgirl [31]

Answer:

Speed at which it will reach the ground is given as

$v_f = 46.8 m/s$

Total time for which it will remain in air is given as

t = 6.3 s

Explanation:

As we know that the object is projected upwards with speed

$v_i = 15 m/s$

$g = - 9.81 m/s^2$

now when it will reach the ground then we have

$y = v_y t + \frac{1}{2} at^2$

so we have

$-100 = 15 t - \frac{1}{2}(-9.81) t^2$

$4.905 t^2 - 15 t - 100 = 0$

so we have

$t = 6.3 s$

Now speed of the object when it reaches the ground is given as

$v_f = v_i + at$

$v_f = -15 + (9.81)(6.3)$

$v_f = 46.8 m/s$

8 0

3 years ago

Given the indices of refraction n_1 and n_2 of material 1 and material 2, respectively, rank these scenarios on the basis of the

aniked [119]

Answer:

a) order of refraction is a, e, de, c , c) a f g

Explanation:

a) when lightning is refracted it must comply with the law of refraction

.n₁ sin θ₁ = n₂ sinθ₂

sin θ / sin δδa) when lightning is refracted it must comply with the law of refraction

.n1 sin θ₁ = n2 sin θ ₂

Sint θ1 / sin θ2 = n2 / n1

1 we see that the ray deviation is promotional to the ratio of the refractive indices

The order of refraction is a, e, de, c

.b) When a ray passes from a medium with less indicated refraction to a higher index the part of the reflected ray has a phase change of 180º

a) no phase change

b) reflected ray has a phase change of 180º

c) no phase change

d) no phase change

e) there is a phase change

f) these phase changeo

1 we see that the ray deviation is promotional to the ratio of the refractive indices

The order of refraction is a, e, de, c

.b) When a ray passes from a medium with less indicated refraction to a higher index the part of the reflected ray has a phase change of 180º

a) no phase change

b) reflected ray has a phase change of 180º

c) no phase change

d) no phase change

e) there is a phase change

f) ay phase vabio

7 0

3 years ago