Homework Sourse1 I need some help with my riding lawn mower In the table th
1. I need some help with my riding lawn mower. In the table that I have above you should be able to calculate the following problem. Can you determine the power that is required, in watts, for the drive motor to overcome friction and operate at this speed. Recall that work is the force delivered over the distance and that power is energy in a specific amount of time. You can assume the frictional coefficient includes rolling resistance, cutter resistance, drag etc.
| Ariens 42 in 17hp riding mower spec | value |
| Mass with rider | 260kg |
| Rear wheel radius | 20cm |
| Gas engine power | 17hp |
| Gas engine max temp | 877k |
| Ambient temp | 293k |
| Gas engine efficiency | 0.5 of carnot |
| Gas engine RPM | 1500RPM |
| Two cutting DC motor, power, each | 500W |
| Cutter blade RPM | 1000RPM |
| Cutter blade radius | 20cm |
| Runtime requirement, hours | 2.8 hours |
| 1.440 kWh batter mass | 27kg |
| Max speed required | 3m/s |
| Estimated coefficient of friction while mowing | 0.1 |
Solution
Friction force = mu* m * g = 0.1 * (27 + 260) * 9.8 = 281.26 N
Friction Power = Friction Force * Cutting Speed
= 281.26 * (pi * 1000 / 30 ) * 0.2 = 5.89 KW
Power required to drive mower (operate at this speed) = Friction force * Velocity
= 281.26 *3 = 0.844 kW
Total power required for cutting and operation = 0.844 + 5.89 = 6.734 kW
