1) why do bicycle has a spoke in wheel.or in rem.2)when we take strip of paper and make 2 hole in it ,and insert finger in it,and try to tear it but only one side get tore,not the both side .3)when bicycle is in motion ,why we don't fall.4) when we slow down our speed of cycle ,we fall from side ward,why not from front or back.

answer for 1)coz without spokes how will the wheel rotate just imagine a wheel without spokes then u cant drvi r8 it will go here and there

#3) we dont fall when we r in motion in a bicycle cox when we move the cycle our effective weight (or center of mass balances ezactly i  the centre and no extra weight in left nor in right therfore we dont fall

 

we dont fall front or back becoz the front wheel and back wheel are balalced in weibh but in left or right our body weight or cycles weight dominates hence more effect is in sidewards, just imagine this case with a see saw, the side with more weight goes down first, suppose some heavy man with some  100 kgs sits in the back seat then the cycle will fall backwards if  the boy i the front is lighter