In a projectile weaving machine the projectile travels a total distance of $250 \text{ cm}$ at an average velocity of $25 \text{ m/s}$. If the time period during which it is in motion occupies half of the loom cycle, the maximum loom speed in picks per minute is________.
This solution details the steps to calculate the maximum loom speed in Picks Per Minute (PPM) for a projectile weaving machine, using the provided distance and average velocity.
Ensure consistent units for calculation. Convert the distance from centimeters (cm) to meters (m).
Use the relationship between distance, velocity, and time ($t = d/v$).
$ t_{\text{motion}} = \frac{d}{v} $
Plugging in the values:
$ t_{\text{motion}} = \frac{2.5 \text{ m}}{25 \text{ m/s}} = 0.1 \text{ s} $
The problem states that the time the projectile is in motion ($t_{\text{motion}}$) is half the total loom cycle time ($T_{\text{cycle}}$).
$ T_{\text{cycle}} = 2 \times t_{\text{motion}} $
$ T_{\text{cycle}} = 2 \times 0.1 \text{ s} = 0.2 \text{ s} $
Loom speed is measured in Picks Per Minute (PPM). To find PPM, convert the cycle time from seconds to minutes or use the formula relating seconds per minute to the cycle time in seconds.
$ \text{PPM} = \frac{\text{Seconds per Minute}}{T_{\text{cycle}} (\text{in seconds})} $
$ \text{PPM} = \frac{60 \text{ s/min}}{0.2 \text{ s}} = 300 \text{ picks/min} $
Therefore, the maximum loom speed is 300 PPM.
| Group I | Group II |
| P. Multiphase | 1. Matched cam |
| Q. Projectile | 2. Profile reed |
| R. Air-jet | 3. Crank shaft |
| S. Shuttle | 4. Weaving rotor |
A shuttle loom having 1.75 m reed width is running at 180 rpm. The shuttle enters and leaves the shed at $120^\circ$ and $240^\circ$ angular positions of crankshaft, respectively. If length of the shuttle is 0.25 m, then the mean velocity (in m/s) of the shuttle within the shed is________.