The speed of the boy and his friend at the bottom of the slope is 16.52 m/s.
<h3>Their speed at the bottom</h3>
Apply the principle of conservation of energy,
E(up) - E(friction) = E(bottom)
mg sin(15) + ¹/₂(M + m)u² - μ(M + m)cos 15 = ¹/₂(M + m)v²
![v = \sqrt{2[\frac{mgd \ sin15 \ + \frac{1}{2}(M + m)u^2 \ -\mu (M + m)g cos\ 15 }{M + m}] }](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2%5B%5Cfrac%7Bmgd%20%5C%20sin15%20%5C%20%2B%20%5Cfrac%7B1%7D%7B2%7D%28M%20%2B%20m%29u%5E2%20%5C%20-%5Cmu%20%28M%20%2B%20m%29g%20cos%5C%2015%20%7D%7BM%20%2B%20m%7D%5D%20%7D)
where;
- u is the speed of the after 28 m
u = √2gh
u = √(2gL sin15)
u = √(2 x 9.8 x 28 x sin 15)
u = 11.92 m/s
![v = \sqrt{2[\frac{(30)(9.8)(70) \ sin15 \ + \frac{1}{2}(30 + 50)(11.92)^2 \ - 0.12 (30 + 50)9.8 cos\ 15 }{30 + 50}] }\\\\v = 16.52 \ m/s](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2%5B%5Cfrac%7B%2830%29%289.8%29%2870%29%20%5C%20sin15%20%5C%20%2B%20%5Cfrac%7B1%7D%7B2%7D%2830%20%2B%2050%29%2811.92%29%5E2%20%5C%20-%200.12%20%2830%20%2B%2050%299.8%20cos%5C%2015%20%7D%7B30%20%2B%2050%7D%5D%20%7D%5C%5C%5C%5Cv%20%3D%2016.52%20%5C%20m%2Fs)
Thus, the speed of the boy and his friend at the bottom of the slope is 16.52 m/s.
Learn more about speed here: brainly.com/question/6504879
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Answer:
9.66 x 10^-6 m
Explanation:
Use the Wein's displacement law

Where, b is the Wein's constant
b = 2.898 x 10^-3 meter-kelvin
So, λm x 300 = 2.898 x 10^-3
λm = 9.66 x 10^-6 m
Full moon!
when Earth is exactly between the Moon and Sun, Earth's shadow falls upon the surface of the Moon, dimming it and sometimes turning the surface red over the course of a few hours.
Answer:
The arrange marriage and love marriage is same or different from each other "one is about loving and then getting committed and another one is getting committed and then loving,so in the either way both are same."
Explanation:
There is no difference at all! Because eventually, in both the cases, people manage to stay together and share the responsibilities. What actually matters is that, if Love happened.
Let’s put it this way. Two people fell in love and they get married, but why is that the same couple would want to separate later? Let’s take another example. Two people who don’t have any idea of each other’s existence get married. why is that they choose to live together forever? Love becomes the reason for any split or patch.
When two people are in love everything becomes easy. A relationship doesn’t look hard, in fact I have friends who have a wonderful married life and people still don’t bother to find if that’s a love or an arranged match. Few of them choose partners of their own and few of them fell head over heels in love with their spouse, but all of them look as if they are on an extended holiday.