## mayankdevnani 3 years ago Question below ::::::::::

1. mayankdevnani

A body of mass 6 kg is under a force of 6 N which causes displacement in it given by $S=\frac{t^2}{4}m$.The work done by the force in 2 s is-

2. mayankdevnani

@amistre64 @ParthKohli @ajprincess @aroub @UnkleRhaukus @experimentX @ganeshie8 @gerryliyana @CliffSedge @mahmit2012

3. CliffSedge

Work = force × distance. Plug in your t=2s to solve for s, then multiply.

4. mayankdevnani

w=6*s

5. mayankdevnani

@phi have a look

6. mayankdevnani

$S=\frac{2^2}{4}=1$

7. mayankdevnani

right @ajprincess and @phi

8. ajprincess

yup perfect:)

9. phi

yes. s is 1 meter force is 6 N work is 6 N-m

10. mayankdevnani

sure @phi

11. phi

of course N-m is a joule so 6 joules

12. mayankdevnani
13. mayankdevnani

@phi

14. phi

Q14 does not say the force is 6 N.

15. mayankdevnani

it says 3J but you say 6J

16. phi

the question says "6 kg under a force that causes a displacement..." we need to find F, using F= ma we need a use d = 1/2 a t^2 we know d and t so we find a, then F and finally W = F d

17. mayankdevnani

@Aperogalics

18. phi

d (or s) in this case is 1 m t is 2 sec 1 = 1/2 a 2^2 a= 1/2 m/s^2 F= ma = 6*1/2 = 3 N W = F d = 3N * 1m = 3 N-m = 3 J

19. mayankdevnani

so my question is also same @phi

20. phi

your question says: mass 6 kg is under a force of 6 N ... you gave the force as 6 N so that is what I would use....

21. mayankdevnani

what do you mean? @phi

22. phi

Q14 requires that you find the force... Your 1st question may be inconsistent? i.e. 6 kg and 6 N don't mesh with the displacement?

23. mayankdevnani

oh!!

24. mayankdevnani

thnx..... @phi