Question

A car going along straight line with a uniform speed of 24 m/s passes a motorcycle at rest. As it passes, the motorcycle starts up, accelerating at 3.2 m/s^2 . If the motorcycle can keep up that acceleration, how long will it take for it to catch the car
(a) 12 s (b) 14 s (c) 18 s (d) none of these
@Physics

Answer 1

none of these

Answer 2

Is the velocity of motorcycle 3.2m/s?

Answer 3

no

Answer 4

apply this:
when the car passes the the bike, the car is moving at 24m/s, the bike is at rest
calculating from that time, if i say, the bike will overtake the car in t seconds, the car will go 24 t meters, the bike will go 1.6 t^2 meters
equate those
u will get the answer as 15 seconds :)

Answer 5

Why the bike will go 1.6t^2 m?

Answer 6

the formula is :
distance covered by an accelerating body in t seconds:
ut+.5at^2
where u= initial velocity, a=acceleration
here, u=0 (as at rest initially), a= 3.2
so, the bike will go 1.6 t^2 meters :)

Answer 7

u got it??

Answer 8

How do you remember those formulas?

Answer 9

just practice :)

Answer 10

and these are fundamental formulae in kinematics

Answer 11

Which grade are you in ?

Answer 12

11, u?

Answer 13

8

Answer 14

oh! then its quite a tough problem for u, i guess :)

Answer 15

Yes, day after tomorrow I have NTSE exam. And these types of questions are common in it.

Answer 16

oh! i am a ntse scholar too :)

Answer 17

Congrats

Answer 18

Which place do you belong to?

Answer 19

west bengal. u?

Answer 20

Tamil Nadu

Answer 21

Can't this be solved without using those formulas.

Answer 22

good place! i love chennai! and idli, dhosa, shambar :)

Answer 23

Have you visited Kalpakkam ?

Answer 24

well, i dont think it can be solved without formulae, and i guess these formulae are in ntse syllabus

Answer 25

Where can I get these Formulae ?

Answer 26

well, i am giving u those

Answer 27

Thanks

Answer 28

http://en.wikipedia.org/wiki/Kinematics

Answer 29

though it will be tough for u to understand