Question

Two cars are at rest, facing each other and 200m apart. If Car 1 accelerates at 6.00m/s^2 up to maximum speed of 30.0m/s and Car 2 accelerates at 5.00m/s^2 up to a maximum speed of 35.0m/s, how long does it take he cars to meet?

Answer 1

its a problem of kinematics

Answer 2

Time to for car 1 to reach max velocity is 5 second and 7 seconds for car 2

Answer 3

then i used d=vo+1/2at^2 to find the distance for the cars at 5 and 7 seconds and i got for 5 seconds car 1 and 2 are 75 and 62.5. For 7 seconds i got 147 for car 1 and 122.5 for car 2

Answer 4

all i know is the collision point is between 5 and 7 seconds, im stuck there

Answer 5

for first car caluclate distance taking initial speed as 0m/s and final speed as 30m/s and acceleration as 6m/s^2

Answer 6

then in similar way caluclate for second

Answer 7

for car 1 i got D 75m, T 5s, and car 2 i got D 122.5m, T 7 s

Answer 8

hey@bukloon ur half way
now take the cars acceleration as 0m/sec^2

Answer 9

you mean make acceleration for both cars and make them 0m/sec^2?

Answer 10

total distance will be 200-(75+122.5)
and then s=(u1*t+2)+u2*t)
2.5=(30*t+2)+(35*t)
then caluclate it for t
t+7 wud be the answer

Answer 11

ha ya @BukLoon b'cause in question its mentioned that the max. speed so after acquiring that speed there wud be no acceleration

Answer 12

they wud b moving vth a constant speed

Answer 13

I cant picture they both stop acceleration once they reach their constant speed

Answer 14

can**

Answer 15

answer is 6.08 s

Answer 16

hmm so i got somewhere wrong stop i will check it out

Answer 17

k the first car accelerated for 5 sec
and in nxt two sec its travellling its travelling 60mts so problem is here

Answer 18

so now caluclate distaance for 5sec for second car

Answer 19

75+60

Answer 20

noo i will make u understand

Answer 21

in first 5 sec first car reached max speed that is 30m/sec
bt second in first 5 sec didn't reach its max speed and its accelerating and it travelled 62.5mts

Answer 22

did u get that till now

Answer 23

yah im at that part, so at 7 seconds car one would be going 135 m and car 2 would be going 122.5

Answer 24

hmm that is beyond 200mts

Answer 25

so now we must apply uniform motion for first car after 5 sec and accelerated mation for second car

Answer 26

so now s=200-(75+62.5)
s=u1*t+(u2*t+1/2*a*t^2)
so, 62.5=30*t+(25*t+1/2*5*t^2)

Answer 27

did u get it.......@BukLoon

Answer 28

yes its worked out, thanks you
Ravi!

Answer 29

mention not .............@ BukLoon

Answer 30

did u understand...........

Answer 31

d=vt+(vit+1/2at^2)