Answer:
42000N
Explanation:
First you calculate how much it would contract, and secondly you then calculate the force to stretch it by that amount.
1) linear thermal expansion coef brass 19e-6 /K
∆L = αL∆T = (19e-6)(1.85)(110) = 0.00387 meter or 3.87 mm
Second part involves linear elasticity.
for brass, young's modulus is 15e6 psi or 100 GPa
cross-sectional area of rod is π(0.008)² = 0.0002 m²
F = EA∆L/L
F = (100e9)(0.0002)(0.00387) / (1.85)
F = 42000 or 42 kN
Answer
given,
radius of earth,r = 1.5 x 10¹¹ m
Time,T = 365 days
= 365 x 24 x 3600 s
earth velocity,


v = 3 x 10⁴ m/s
centripetal acceleration of the earth


a = 6 x 10⁻³ m/s²
1) KE=1/2*m*v^2
1/2*45*40^2
KE=36,000J
2) PE=mgh
45*9.81*30
PE=13243.5J
It would be D) the rope is pulled to the right. This is because their is a greater force in that direction.