10.If a bus accelerates from rest for time t1,at a constant rate α and then retards at a constant rate β for time t2 and comes to rest, then t1/t2=

solution:

a bus initial velocity u=0

for time =t1

acceleration = α

after time t1 ,the velocity will be v1=αt1

this velocity will become initial velocity for retarded motion, u=αt1

then retards with acceleration =-β

for time =t2

this is given information ,

for time t2 ,the body retards

v2= αt1-βt2

but v2 is nothing but is zero

0=αt1-βt2

t1/t2=β/α