A girl swings on a playground swing in such a way that at her highest point she is 4.1 m from the ground, while at her lowest po
1 answer:
Answer:
V1 =8.1 m/s
Explanation:
height at highest point (h2) = 4.1 m
height at lowest point (h1) = 0.8 m
acceleration due to gravity (g) = 9.8 m/s^{2}
from conservation of energy, the total energy at the lowest point will be the same as the total energy at the highest point. therefore
mgh1 + = mgh2 +
where
- speed at highest point = V2
- speed at lowest point = V1
- mass of the girl and swing = m
- at the highest point, the speed is minimum (V1 = 0)
- at the lowest point the speed is maximum (V2 is the maximum speed)
- therefore the equation becomes mgh1 +
= mgh2
m(gh1 + ) = m(gh2)
gh1 + = gh2
V1 =
now we can substitute all required values into the equation above.
V1 =
V1 =
V1 =8.1 m/s
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Answer:
A) x _electron = 0.66 10² m , B) x _Eart = 1.13 10² m , C) d_sphere = 1.37 10⁻² mm
Explanation:
A) Let's use a ball for the nucleus, the electron is at a farther distance the sphere for the electron must be at a distance of
Let's use proportions rule
x_ electron = 0.529 10⁻¹⁰ /1.2 10⁻¹⁵ 1.5
x _electron = 0.66 10⁵ mm = 0.66 10² m
B) the radii of the Earth and the sun are
= 6.37 10⁶ m
tex]R_{Sum}[/tex] = 6.96 10⁸ m
Distance = 1.5 10¹¹ m
x_Earth = 1.5 10¹¹ / 6.96 10⁸ 1.5
x _Eart = 1.13 10² m
C) The radius of a sphere that represents the earth, if the sphere that represents the sun is 1.5 mm, let's use another rule of proportions
d_sphere = 1.5 / 6.96 10⁸ 6.37 10⁶
d_sphere = 1.37 10⁻² mm