The best answer is b - span.
A span is the distance between two bridge supports The supports may be towers, columns, or even the wall of a canyon.
There are many kinds of bridges but they all fall into three types namely beam, arch and suspension. The major difference between these three kinds of bridges is the distance that each can cross in a single span.
For example, a modern beam bridge is likely to span a distance of 200 feet, a modern arch can span 800 or 1000feet, and a modern suspension bridge can span up to 7000ft.
Answer:
x' = 1.01 m
Explanation:
given,
mass suspended on the spring, m = 0.40 Kg
stretches to distance, x = 10 cm = 0. 1 m
now,
we know
m g = k x
where k is spring constant
0.4 x 9.8 = k x 0.1
k = 39.2 N/m
now, when second mass is attached to the spring work is equal to 20 J
work done by the spring is equal to


x'² = 1.0204
x' = 1.01 m
hence, the spring is stretched to 1.01 m from the second mass.
gravity, inertia, friction, kinetic energy?
A scientific control: Is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.<span />