Can someone help me

RSB [31]

Answer:

One may assume that the planet radiates energy like a blackbody at some temperature according to the Stefan–Boltzmann law. Thermal equilibrium exists when the power supplied by the star is equal to the power emitted by the planet. The temperature at which this balance occurs is the planetary equilibrium temperature.

Explanation:

6 0

3 years ago

(a) Find the position vector of a particle that has the given acceleration and the specified initial velocity and position. a(t)

dolphi86 [110]

Answer:

$r(t)=(\frac{10t^3}{3}+t)i+(-sint+t+1)j+(\frac{-cos2t}{4}+\frac{1}{4})k$

Explanation:

a(t)=20t i+sin(t) j +cos(2t) k

v(t)= $\int\limits^a_b {a(t)} \, dt$

= $(10t^2+c_1)i+(-cost+c_2)j+\frac{sin2t}{2}k$ ---------------eqn 1

given v(0)=i

i= $c_1i+(-1+c_2)j+(0+c_3)k$

$c_1=1$ $c_2=1$ $c_3=0$

from equation 1

V(t)= $(10t^2+c_1)i+(-cost+c_2)j+\frac{sin2t}{2}k$ ----------eqn 2

now r(t)= $\int\limits^a_b {v (t)} \, dt$

$(\frac{10t^3}{3}+t+c_1)i+(-sint+t+c_2)j+(\frac{-cos2t}{4}+c_3)k$

given r(0)=j

0i+1j+ok = $c_1i+c_2j+(\frac{-1}{4}+c_3)k$

$c_1=0$ $c_2=0$ $c_3 = \frac{1}{4}$

$r(t)=(\frac{10t^3}{3}+t)i+(-sint+t+1)j+(\frac{-cos2t}{4}+\frac{1}{4})k$

8 0

3 years ago

Suppose you have a hypothesis you believe to be correct what should you do to make you become a theory

LenKa [72]

D. Collect more evidence and try to convince the other scientist

6 0

4 years ago

What is the least value of an ammeter Is it 1. 0.1 2. 0.10 3. 0.2 4. 0.5

givi [52]

The least value varies depends on ammeter range. In the given question, ammeter range is not mentioned. So, the least value of an ammeter is 0.1 or 0.5 (depends on ammeter range).

Explanation:

The least value of an ammeter is the measure of the smallest number which can be observed in ammeter. So the least value will be varying depending upon its range. If we consider the range of ammeter is 30 A and the scale readings are 10 numbers, then the least value will be 30/10 = 3 A per scale.

So the least value is determined as $\frac{Range of ammeter}{No.of scales}$

So among the given options 0.1 is most suitable for an ammeter with range of 3 A with 30 divisions.

3 0

3 years ago

A cancer or cancerous tumour on the skin as a result of extensive exposure to UV rays.

nekit [7.7K]

Answer:

Almost all skin cancers (approximately 99% of non-melanoma skin cancers and 95% of melanoma) are caused by too much UV radiation from the sun or other sources such as solaria (solarium, sunbeds, and sun lamps).

Explanation:

Skin cancer develops in the cells in the epidermis – the top or outer layer of the skin. UV radiation is made up of UVA and UVB rays which are able to penetrate the skin and cause permanent damage to the cells below:

UVA penetrates deeply into the skin (the dermis) causing genetic damage to cells, photo-ageing (wrinkling, blotchiness etc) and immune-suppression.

UVB penetrates into the epidermis (top layer of the skin) causing damage to the cells. UVB is responsible for sunburn – a significant risk factor for skin cancer, especially melanoma.

If the body is unable to repair this damage the cell can begin to divide and grow in an uncontrolled way. This growth can eventually form a tumor.

UVA and UVB both contribute to sunburn, skin ageing, eye damage and melanoma and other skin cancers.

3 0

4 years ago