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https://github.com/danbulant/notes
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30 lines
No EOL
730 B
Markdown
30 lines
No EOL
730 B
Markdown
---
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tags:
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- fyz/rychlost
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---
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# Rychlost
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## Příklady
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- $t = 2,5h$
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- $s = 180km$
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- $V_p = s/t$
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- $V_p = 180/2,5 km/h$
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- $V_p = 72 km/h$
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- $3/4t = t1$
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- $v_1 = 90km/h$
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- $1/4t = t2$
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- $v_2 = 50km/h$
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- $v_p = ?$
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- $v_p = s/t = (v_1 * t_1 + v_2 * t_2)/(t_1 + t_2)$
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- $v_p = (90 * 3/4t + 50 * 1/4t)/t = t((90*3)/4 + 50/4)/t = 320/4 = 80km/h$
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- $s_1 = 3/4s$
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- $s_2 = 1/4s$
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- $v_1 = 90km/h$
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- $v_2 = 50km/h$
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- $v_p = ?$
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- $v_p = s/t = (s_1 + s_2)/t = (3/4s + 1/4s)/3/4 *v2 + 1/4 * v_1/v_1v_2 = s*v_1*v_2/s(3/4v_2 + 1/4v_1) = v1 * v2/(3/4v_2+ 1/4v_1) = 90 * 50/(¾ * 50 + ¼ * 90) = 90 * 50 * 4/ 150 + 90 = 75km/h$
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- $t = s/v$
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- $t_1 = 2h$
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- $v_1 = 6km/h$
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- $v_2 = 3km/h$
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- $t_2 = 1h$
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- $v_p = s/t = t1 * v1 + t2 * v2/t = 12 + 3/3 = 5$ |