Question

d of front &rear wheel of tractor is 21cm&84cm .find the no of revolution that the rear wheel makes to convert the dist which front wheel covers in 20 sec at a speed of 252 km/h

Answer 1

PLEASE MARK IT AS BRAINLIST!!!!!

First find the distance covered by the front wheel in 20 seconds.

Change the speed 252km/hr of the front wheel into meter/second    252km/hr

=252 km1 hour                    
=252×1000 m3600 sec                    
=252×1000 m3600 sec                    
=70 m/s
So distance covered by front wheeel in 20 seconds is,    
20×70=1400 m                 
=1400×100 cm                 
=140000 cm
The circumference of the rear wheel is    
πd=227×84 cm          
=22×12 cm         
 =264 cm
Therefore the required number of rotations are,      
140000264=530.3
That is 530 rotation