Answer:
0.6375 m/s
Explanation:
Let x be the distance of the man from the building
from the figure attached
initially the value of x=12
Given:

where the negative sign depicts that the distance of the man from the building is decreasing.
Now, Let The length of the shadow be = y
we have to calculate
when x=4
from the similar triangles
we have,
or

Differentiating with respect to time 't' we get

or

Now for x = 4, and
we have,

or

<u>here, the negative sign depicts the decrease in length and in the question it is asked the decreasing rate thus, the answer is </u><u>0.6375m/s</u>
It depends on the size of the star. If it's size was normal then it cools down into White dwarf, then a black dwarf. If a really huge star dies, then we can see a "Supernova" from that.
Hope this helps!!
Answer:
The speed of the cart and clay after the collision is 50 cm/s .
Explanation:
Given :
Mass of lump , m = 500 g = 0.5 kg .
Velocity of lump , v = 30 cm/s .
Mass of cart , M = 1 kg .
Velocity of cart , V = 60 cm/s .
We know by conservation of momentum :

Here ,
is the speed of the cart and clay after the collision .
Putting all value in above equation .
We get :

Hence , this is the required solution .
The wavelength of the radio waves is 3.04 cm.
<h3>Calculation:</h3>
λf = c
λ = c/f
where,
λ = wavelength
c = speed of light
f = frequency
Given,
f = 98.6 MHz = 98.6 × 10⁶
c = 3 × 10⁸
To find,
λ =?
Put the values in the formula,
λ = c/f
λ = 3 × 10⁸/98.6 × 10⁶
= 0.0304 × 10² m
= 3.04 cm
Therefore, the wavelength of the radio waves is 3.04 cm.
Learn more about the calculation of wavelength here:
brainly.com/question/8422432
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