What is the retarding force required to bring an object of 5 kg, travelling with a speed of 40 km/h, completely to rest in a distance of 250 mm? Share with your friends Share 0 Anshu Agrawal answered this Solution: The initial velocity of the stone, u= 40km/hr =40×518=11.1m/s The final velocity of the stone, v= 0 Distance covered by the stone, s= 250 mmMass of stone, m = 5kgUsing the formulav2 -u2 =2as0-(11.1)2=2×a×250×10-3-123 =0.5aor a =-246m/s2Here, -ve sign shows retardation.Force =ma =-5×246 =1230 NHere, -ve sign shows force is in the opposite direction. 0 View Full Answer