#Vector Problem | Need Help

31 messages · Page 1 of 1 (latest)

frosty bay
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Can't figure out:

I know -

The magnitudes are:
Pedal down = 10 N
Shafts length = 20cm = 0.2m

Sine Theta Angle Between:
Shafts position = pi / 6 = 30 degrees

The torque's magnitude of the bike = the perpendicular vector's magnitude on the point where the shaft and pedal are involved

(10)(0.2)sin(30) = 1 Nm

What's the error??

ebon ploverBOT
frosty bay
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<@&286206848099549185> Help !

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@hard pewter Can you help please?

hard pewter
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Are you sure that the component of the force isn't 10cos30?

frosty bay
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I entered 5sqrt(3) it doesn't work

hard pewter
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component of the force is still multiplied by distance to get torque, so I am suggesting sqrt{3} Nm

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When you resolve the vertical force into components perpendicular to and parallel to the shaft, the perpendicular component is adjacent to the 30 degree angle, hence cosine

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Assuming that I am reasoning this correctly

brittle ember
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Yeah

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You need to take into account the force which is going to be applied from a completely vertical force

frosty bay
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@brittle ember @hard pewter Can you expand more fully, I don't understand the logic fully

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And why the other approach was wrong

brittle ember
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The torque force is perpendicular

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Which would be tangential to the circular path

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So a completely vertical force excerted on the shaft would be the only ocassion where the torque force is equal to length times the force

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Is it alright if i send a diagram to show how it works?

frosty bay
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Yes, I still don't fully get it

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Visual illustration would probably help

frosty bay
brittle ember
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Right

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With this value for the force (5 sqrt(3) not 10 (i used the wrong value its 10 not 20)) applied we just need to multiply it by the lenth radius to get the torque

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$t= F\times L \newline$
$t=t\sqrt{3} \times 0.2 \newline$
$t=\sqrt{3} Nm$

copper jackalBOT
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imdeadinside4630

brittle ember
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@frosty bay