## pratyush5 2 years ago A body looses half of its velocity while penetrating 3 cm into a wooden block, then how much will it penetrate more before finally coming to rest. Please explain

1. pratyush5

@ashwinjohn3 @yrelhan4 @uri

2. pratyush5

i have got the answer but i want to know a proper method

3. yrelhan4

newtons law of motion will do it for you!

4. pratyush5

i used v^2 - u^2 = 2as

5. pratyush5

i just need to know what should i take for acceleration or should i ignore it

6. ashishthomas7

u must find the acceleration dude....

7. ashwinjohn3

Ok....Acceleration is negative since it is slowing down.....

8. pratyush5

ya sure

9. ashishthomas7

here v=u/2,and use the equation v^2=u^2-2as

10. ashishthomas7

then u will get accelration

11. ashishthomas7

then finally equate v=0,a=obtained from above and find s!!!

12. ashishthomas7

since here the question asked is "how much more will it penetrate" initial velocity=u/2...

13. pratyush5

i am getting a= -u^2/8

14. pratyush5

is dat right ?

15. yrelhan4

yup..

16. ashishthomas7

yup....

17. pratyush5

there fore the equation for finding "s" should be|dw:1359144797548:dw| right

18. pratyush5

so i get s=1 cm

19. ashishthomas7

i got that too...

20. pratyush5

correection |dw:1359144893116:dw|

21. pratyush5

thnku all

22. ashishthomas7

23. yrelhan4

yes.. i was wondering whats wrong. so s=4cm. it penetrates 1cm more.

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