Question

1 - Your Physics teacher is giving you a special gift, a box of mass 20
kg with a mystery surprise inside. The box is placed on a
frictionless table,
(a) What is weight of the box and normal reaction over it by the table?
(b) If you pushes down that box with 80 N, Now what is
Normal Reaction in this case?
(c) If you pulls up that box with 80 N, Now what is Normal
reaction in this case?
(d) What happens, if you pulls up that box with 200 N force
rather than 80 N?
(e) To guess what is inside, if you are pulling it at an angle of 30° with
force 80 N with horizontal, what is
(i) Acceleration of box?
(ii) Normal Reaction exerted on the box by the table?
(f) At the time of pulling it, you are saying to your teacher 'Sir, What
the force I am applying on box, same force box is applying on me
(Action - Reaction Pair), these two forces are getting balanced so I
can not pull it.. Justify this Statement !!​

Answer 1

Answer:

1. 200N
2. 200N
3. 120N
4. 0N
5. 2meter per second square
6. 200-80 cos 30
7. if box is at equilibrium u need to apply more force for motion..but you can't so it cannot have acceleration

if you have any doubt are these answers so please ask me...