| Forum Home | ||||
| PC World Chat | ||||
| Thread ID: 77796 | 2007-03-22 23:45:00 | NCEA Science Homework for the W/E | Terry Porritt (14) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 535159 | 2007-03-22 23:45:00 | Whilst browsing through a Repco flyer today, I saw an ad for a petrol driven waterblaster. Even after all these years since 'decimalisation', they are still using mixed units in the specifications. Pressure: 3000psi Flow rate: 15L/min Engine power: 9hp Hose length: 10m Let's see if the recent dumbing down claims for NCEA are true, here is the problem for all aspiring scientists/engineers in year 13, or first year at tech./university. 1. From the data supplied, calculate the hydraulic pumping power, ie. the power in the quoted flow at the quoted pressure. 2. What is the minimum pump efficiency if the quoted pressure and flow rates are to be achieved simultaneously with the engine power available? Note: consideration of losses in the hose can be ignored for this exercise :) |
Terry Porritt (14) | ||
| 1 | |||||