## AravindG 4 years ago A block of mass M is pulled along a frictionless surface by a rope of mass m.If a force P is applied at the free end of rope ,What will be the force exerted by the rope on the block???

1. 101Ryan101

As the rope pulls the block, the block pulls back with equal force in the opposite direction. So I'll go with 2p. But I'm not sure of that.. Anyone?

2. 101Ryan101

wait that's not right...

3. 101Ryan101

F=ma

4. Ishaan94

see just take mass of rope plus the block and then apply all formulas

5. Ishaan94

like joint bodies

6. Ishaan94

they have reaction forces between them

7. 101Ryan101

(M+m)a = p

8. 101Ryan101

?

9. Ishaan94

| r | <-------rope -------- | r | < --------block so r is the force exerted by the rope on the block r = m(block)a and from the rope equation

10. Ishaan94

f (force applied ) + r = m(rope)a now get r

11. 101Ryan101

Maybe I should thing twice about taking physics. lol

12. Ishaan94

lol no you should take it

13. 101Ryan101

I don't really understand why its F+r on the left side there..

14. Ishaan94

the thing is block | rope |---------------------- R<-| ---------> R |---------------------- | --------------------------------------------------

15. Ishaan94

R is the reaction force or contact force

16. Ishaan94

------------------------------------ ---->R |--------->p ------------------------------------ P + r = m(rope)a

17. 101Ryan101

Are we speaking of the force the rope is "feeling"?

18. Ishaan94

Yeah

19. 101Ryan101

OHHHHH

20. Ishaan94

I didn't draw the normal or perpendicular forces

21. 101Ryan101

but it says "what will be the force by the rope ON THE BLOCK.. lol so I thought that means, what the block is feeling>>

22. Ishaan94

R is the force for the block from the rope

23. Ishaan94

now take a careful look the only force that rope and block have is the R so hence r is the one were looking for

24. 101Ryan101

Is there a name for this type of problem so I can go concentrate on them?

25. Ishaan94

try Rop-mass.......... I don't know i didn't solve them much