Question

A motorist traveling at 15m/s encounters a deer in the road 43m ahead. If the maximum acceleration the vehicle's brakes are capable of is -6m/s/s, what is the maximum reaction time of the motorist that will allow him to avoid hitting the deer?
Answer in units of s.

Answer 1

ok first use v^2=vi^2+2ax

Answer 2

find initial speed

Answer 3

I haven't learned that formula yet, so I shouldn't have to use it...

Answer 4

what did u learned

Answer 5

\[v=d/t, a=(v _{f}-v _{o})/t, v(average)=(v _{o}+v _{f})/2, d=(1/2)at ^{2}, and d _{f}=d _{o}+v _{o}t+(1/2)at ^{2}\]

Answer 6

use 4th one

Answer 7

d=1/2

Answer 8

.....

Answer 9

v=u+at...put v=0,u=15...withacc.=-6...

Answer 10

Should that get me the answer then?

Answer 11

ya it will give u min. time when vechicle stops...put that in eq. s=ut+1/2at^2 u will get distance...

Answer 12

I don't understand what you just said, but I used the first equation thing you gave me, plugged in the stuff you told me to and got the wrong answer

Answer 13

@ksaimouli I tried what you told me to do and also got the wrong answer

Answer 14

use eq. s=ut+1/2at^2...put s=43,u=15,a=-6

Answer 15

ok i am giving the solution

Answer 16

@pkjha3105 I've tried that

Answer 17

try...u may get ans. easily by dis methrd..

Answer 18

I ALREADY DID TRY