+1 vote
in Farm Machinery by (38.9k points)
A mower has driven wheel of 60 cm diameter. The crank of mower makes 550 rpm, when it is driven by a tractor at a speed of 2 km/h. If speed ratio between the crank wheel and land wheel is changed to 27:1, calculate the increase in speed of mower to maintain the same speed of crank.

(a) 0.20 km/h

(b) 0.304 km/h

(c) 1.402 km/h

(d) 1.36 km/h

This question was posed to me in an interview for job.

Enquiry is from Harvesting Equipments topic in portion Harvesting Equipments of Farm Machinery

1 Answer

+2 votes
by (243k points)
selected by
Best answer
Right option is (b) 0.304 km/h

For explanation: \(\frac{Nc}{Nl}=\frac{27}{1} \)

Nl=\(\frac{Nc}{27}=\frac{550}{27}\) = 20.38 rpm

Linear speed of mower, V = \(\frac{πDNc}{60} = \frac{π*0.6*20.38}{60}\) = 0.640 = \(\frac{0.640*3600}{1000}\) = 2.304 km/h

Increase in speed = V2 – V1 = 2.304-2 = 0.304 km/h.

Related questions

We welcome you to Carrieradda QnA with open heart. Our small community of enthusiastic learners are very helpful and supportive. Here on this platform you can ask questions and receive answers from other members of the community. We also monitor posted questions and answers periodically to maintain the quality and integrity of the platform. Hope you will join our beautiful community