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2. kūno slinkimas ir sukimasis

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τ<br />

a B = ε 4 ⋅ a 4 ,<br />

ε<br />

a<br />

4<br />

τ<br />

B<br />

4<br />

68<br />

= ω′ = −2,<br />

78 rad/s<br />

= −0,<br />

334 m/s<br />

Kadangi e4 < 0, w4 > 0, tai ratai 4 sukasi lėtėdami,<br />

pav., b).<br />

Taško B normalinis pagreitis<br />

n<br />

2<br />

a<br />

n<br />

B<br />

= ω<br />

2<br />

4<br />

⋅ a<br />

4<br />

=<br />

2<br />

.<br />

( 5,<br />

56<br />

−<br />

2<br />

,<br />

B<br />

τ<br />

B<br />

v <strong>ir</strong> a kryptys priešingos (<strong>2.</strong>13<br />

2,<br />

78t)<br />

kai t = 1 s, a B<br />

Tada<br />

= 0,<br />

927 m/s <strong>ir</strong> nukreiptas į rato 4 sukimosi ašį.<br />

a<br />

B<br />

=<br />

0,<br />

334<br />

Mažasis 4 <strong>ir</strong> didysis 3 ratai apjuosti d<strong>ir</strong>žu, todėl<br />

Taško P greitis<br />

2<br />

+<br />

0,<br />

927<br />

2<br />

=<br />

2<br />

⋅ 0,<br />

12,<br />

0,<br />

986 m/s<br />

vL=vF, vL=w4×r4, vF=w3×R3, w4×r4=w3×R3,<br />

ω<br />

3<br />

ω4r<br />

=<br />

R<br />

3<br />

4<br />

=<br />

vP = ω3<br />

⋅ r3<br />

=<br />

( 5,<br />

56<br />

( 2,<br />

1<br />

−<br />

−<br />

2,<br />

78t)<br />

0,<br />

16<br />

1,<br />

04t)<br />

⋅<br />

⋅<br />

0,<br />

06<br />

0,<br />

08<br />

=<br />

=<br />

2<br />

.<br />

( 2,<br />

1<br />

( 0,<br />

17<br />

Kūnas E pr<strong>ir</strong>ištas prie v<strong>ir</strong>vės, užvyniotos ant mažojo rato 3, todėl<br />

vE=vP=(0,17 - 0,083t) m/s.<br />

Kai t = 1 s, vE = 0,087 m/s. Kūnas E keliamas į v<strong>ir</strong>šų (<strong>2.</strong>13 pav., b).<br />

Kūnas E slenka, todėl jo pagreitis<br />

= v′<br />

( 0,<br />

17<br />

Kadangi aE < 0 , vE > 0 , tai kūnas E kyla lėtėdamas.<br />

a<br />

E<br />

E<br />

=<br />

−<br />

0,<br />

083t)<br />

−<br />

′ = −0,<br />

083 m/s<br />

−<br />

2<br />

1,<br />

04t)<br />

0,<br />

083t)<br />

.<br />

rad/s.<br />

m/s.

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