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4. When the motor is turned on it rotates at 240
rev/min (rpm) |
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| If gear Z rotates once then gear Y moves 3 times |
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| As gear Y has more teeth than gear Z then rpm is reduced |
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| Gear Y = 80 rpm |
| Gears X and Y are combined to form a compound gear. Therefore, gear X rotates at the same speed as Y |
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Gear X = 80 rpm |
| (ii) How far does the platform travel in one minute? |
| Gear X has 13 teeth. This number is multiplied by the
80 rpm giving the distanced moved in terms of number of teeth. 13 x 80 = 1040 teeth |
| The rack moves the same number of teeth as it meshes with gear X. |
| To convert this distance into millimetres 1040 (teeth) x 4mm (the pitch or distance between the teeth) = 4160mm |
