Subject :NSO Class : Class 8
There are three long planks, each of length 5 meters.
Three identical balls are placed on the planks as shown in the figure.
Frictional force offered by planks I, II and III on the ball are f1, f2 and f3 respectively.
If same force (push) is given to each ball then time taken to leave the planks I, II and III are 2 minutes, 1 minute and 4 minutes respectively.
Which of the following options is correct regarding the friction force offered by the planks on the ball?
Af1 = f2 = f3
Bf1 > f2 = f3
Cf3 > f1 > f2
Df3 < f1 < f2