Question

two cars P and Q start from a point at the same time in a straight line and their position are reprensted by xp= 4t-2t^2​

Answer 1

Explanation:

Step 1: Calculate velocity of car P and Q

V

P

=

dt

d[x

P

(t)]

=

dt

d

(at+bt

2

) =a+2bt ....(1)

V

Q

=

dt

d[x

Q

(t)]

=

dt

d

(ft−t

2

)=f−2t ....(2)

Step 2: Time at which both have the same velocity

Let t

0

be the time when V

P

and V

Q

are same

Equate equation (1) and (2)

V

P

∣

t=t

0

=V

Q

∣

t=t

0

⇒a+2bt

0

=f−2t

0

⇒ t

0

=

2(b+1)

f−a

Hence, Option(A) is correct.