Answer:
t = 5.56 s
Explanation:
In order to calculate the time interval taken by the mountain biker to come to a stop, we will use third equation of motion and first find the deceleration:
2as = Vf² - Vi²
where,
a = deceleration = ?
s = distance = 15 m
Vf = Final Velocity = 0 m/s
Vi = Initial Velocity = 5.4 m/s
Therefore,
2a(15 m) = (0 m/s²) - (5.4 m/s)²
a = - 0.972 m/s²
Now, we use 1st equation of motion:
Vf = Vi + at
therefore,
0 m/s = 5.4 m/s + (-0.972 m/s²)(t)
t = (5.4 m/s)/(0.972 m/s²)
<u>t = 5.56 s</u>
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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As you approach the surface of the sphere very closely, the electric field should resemble more and more the electric field from an infinite plane of charge.
If you check Gauss's law (recalling that the field in the conductor is zero) you will see that if the surface charge density is σ=Q/4πR2, then indeed the field at the surface is σ/ϵ0 as in the infinite charge of plane case.
Such a field is constant, the field lines are parallel and non-diverging, and the infinities associated with the field due to point charge do not arise.
Explanation:
<span>150 kPa
While Titan is Saturns largest moon, it only has a mass of 0.0225 Earths
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