TRACK Youm PROGRESS
3. Observe the forces acting on boxes A, B and C.
SNBAN
3N-
BB N NBC
4N-
direction
a. Box A will move towards
b Box B will
Box C will move towards
d. Net forces on Boxes A, B and Care
direction
4. What will be the pressure exerted by a solid if it exerts 700 N of fonden
area of 7 m?
5. A pressure of 60 Pa acts on a smooth surface of area 2 m. Calculate the
applied on the surface.
Answers
Explanation:
Correct options are B) and D)
Given,
Each sphere is of mass, mkg
Upward acceleration, a=
4
g
Total mass of box contains three spheres, 3mkg
(i) Net normal force on base of box, N=3mg+3ma=3mg+3m
4
g
=
4
15mg
(ii) Horizontal component of normal reaction at center of A,
N
1
sin30
o
=N
2
sin30
o
N
1
=N
2
=N
Vertical component of normal reaction at center of A,
N
1
cos30
o
+N
2
cos30
o
=m(g+a)
2Ncos30
o
=m(g+
4
g
)
N=
4
3
5mg
Hence, net normal reaction at base of box is
4
15mg
, and normal reaction on A is
4
3
5mg
.
Answer: a) Box A will move towards the right direction.
b) Box B will not move.
c) Box C will move towards right direction.
d) Net forces on Boxes A, B and C are 5N, 0 and -1N
4. What will be the pressure exerted by a solid if it exerts 700N of force on an area of 7m^2?
Pressure=Force/Area
Answer:- Pressure= 100 Pa.
5. A pressure of 60 Pa acts on a smooth surface of area 2m^2. Calculate the force applied on the surface.
Answer:- Force = Pressure multiplied by Area
Force= 120N
Explanation: