1the ans is (c)
A car accelerates from rest at a constant rate a for sometime after which it decelerates at a constant rate b to come to rest. If the total time lapse is t second.then the max. velocity reached is:
a) abt2/a+b
b) abt/a-b
C) abt/a+b
d) Zero
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4 Answers
62A car accelerates from rest at a constant rate a for sometime after which it decelerates at a constant rate b to come to rest. If the total time lapse is t second.then the max. velocity reached is:
at1 = bt2
t1+t2=t
solve both of these you will get the answer :)
1let max^m vel be v & time taken to attain be t1
car accelrates from rest
v=0+at1
v=at1
t1=v/a
car deccelerates at rate b to rest and let time taken be t2
0=v-bt2
t2=v/b
t=t1+t2
=v(1/a+1/b)
=v(a+b/ab)
v=t(ab/a+b)