<span>The use of the word on instead of the word in when referring to the angular distance between celestial objects comes about because all of the objects appear to be on the celestial sphere and at an indeterminable distance. While we know that objects are at different distances in the sky, their distance from Earth is irrelevant in determining the angular distance between the two objects as viewed from Earth.</span>
Newtons third law (inertia) is to blame
1) C. velocity
Acceleration is defined as the rate of change of velocity per unit time. In formulas:
where
is the change in velocity
is the time interval
Therefore, the correct answer is C. velocity.
2) A. 9.8m/s/s
Earth's gravity is a force, so it produces an acceleration on every object with mass located on the Earth's surface. This acceleration can be calculated, as it is given by the formula
where
is the gravitational constant
is the Earth's mass
is the Earth's radius
By substituting these numbers into the formula, one can find that the acceleration due to Earth's gravity is 
.
Explanation:
<em>a)Which of the two has uniform acceleration?</em>
Acceleration is the second derivative of position. The acceleration of the first particle is:
x = 4t² − 2t
v = 8t − 2
a = 8
The acceleration of the second particle is:
x = 6t³ + 8t
v = 18t² + 8
a = 36t
The first particle has uniform acceleration.
<em>b)Which one is likely to come to rest at some time during its motion?</em>
The particles come to rest when v = 0. The first particle's velocity has a real zero at t = 4. The second particle's velocity has only imaginary zeros, meaning v is never 0.
