Author Question: A vertical 30-cm steel rod, 1.0 cm in diameter, supports a 300-kg mass. What is the change in length ... (Read 54 times)

saliriagwu · **on:** Jul 29, 2018

A vertical 30-cm steel rod, 1.0 cm in diameter, supports a 300-kg mass. What is the change in length of the rod caused by this mass? Young's modulus for steel is 2.0 1011 N/m2.

A) 6.5 10-4 m B) 5.6 10-6 m C) 6.5 10-6 m D) 6.5 10-5 m E) 5.6 10-5 m

Question 2

According to the theory of cosmic inflation, the large-scale clumping of matter (into stars, galaxies, etc.) that we observe in the universe had its origin in

A) the creation of dark matter, that exerted a repulsive force and pushed things together.
B) the creation of dark energy, that exerted an inward force and pulled things together.
C) thermal motion caused by the high temperature of the early universe.
D) quantum nonlocality, that connected bits of energy that were originally separated.
E) quantum uncertainties that were then stretched by the expansion of the universe.