There are three forces acting on the book.
1. Force due to gravity
2. Force exerted downward by the hamster
3. Normal Force in reaction to the downward forces
Since the book is not moving, the net force is zero. The summation of all forces must be zero. Then we could find the normal force which is unknown (denoted as x).
∑F = -(4 kg)(9.81 m/s2) - 3 N + x =0
∑F = -39.24 N - 3N + x =0
x = 42 N
Therefore, the normal force is 42 N.
Answer:
the answer is
Explanation:For equilibrium
Weight = Tension
mg=T
∴T=4×3.1π=12.4πN (as can be inferred from the question)
Y=
△l/l
T/A
=
1000
0.031
/20
12.4π/π(
1000
2
)
2
=
4×0.031
12.4×20×1000×(1000)
2
=2×10
12
N/m
2