A, b, d, c, c, d, a, b, c, b, ultrasound, sound, sonar, harmonics, vibration, true, false, false, true, true
I guess the problem is asking for the distance between Earth and Mars in Astronomical Units (AU).
Since

and the distance between the two planets is

we can convert this distance into AU by using the following proportion:

from which we find
Answer:
F = 24 N
Explanation:
In this exercise we have a bar l = 100 m with a center of gravity x = 4 m, which force is needed to lift it from the other end
Let's use the rotational equilibrium relationship, where we consider the counterclockwise rotations as positive and fix the reference system at the point closest to the center of gravity
∑ τ = 0
F l -x W = 0
F = 
let's calculate
F =
4/100 600
F = 24 N
Answer:
C Restoring Force
Explanation:
Given data
Fs=-kx
According to Hokes Law, provided the elasticity of an elastic material is not exceeded the extension xis directly proportion to the applied force F
From the expression, F represent the Restoring Force in Newton