Answer:
(1) Initial speed, 
Final speed, 
Average speed, 
(2) Force of gravity, 
Explanation:
(1)
Given,
Distance, 
Time, 
It is given that drag racer started at rest.
So Initial speed,
Using Newton's second equation of motion,
Newton's first equation of motion,
So, Final speed,
Average speed is defined as totle distance divided by totle time.
So, Average speed,
(2)
Gravitation: It is the natural phenomenon in which two different bodies attract each other by virtue of their masses.
According to Newton's law of gravitation, the force of attraction between two bodies is directly proportional to the masses of the bodies and inversely proportional to square of distance between centers of mass of the bodies.
where 
is constant of proportionality and known as gravitation constant.
Given,
Mass of Jupiter, 
Mass of Ganymede, 
Distance between their centers of mass, 
So, Force of gravity,
Answer: D. Density of uranium within nuclear fuel rods is insufficient to become explosive
Explanation: Nuclear power plants use the same fuel as nuclear bombs, i.e. radioactive Uranium-235 isotope. However, in a nuclear power plant, the energy is released more slowly unlike in a nuclear bomb. <em>The energy released is through nuclear fission, and radioactive decay occurs at the same rate as in nuclear bombs. therefore, option A, B</em><em> </em><em>and C are incorrect.</em>
The primary reason why nuclear chain reactions within power plants do NOT produce bomb-like explosions is because the uranium fuel rods used in electricity generation is not sufficiently enriched in Uranium-235 to produce a nuclear detonation. This is the same idea in option D which is the correct option.
<span>a) write a polynomial expression for the position of the particle at any time t greater or equal to zero.
</span>Position is found by integrating velocity:
<span>s(t) = (t^3)/3 - 4t^2 + 7t + c
</span>where c is a constant corresponding to the position at t=0. <span>
b) at what time(s) is the particle changing direction
</span>the particle changes direction whenever the velocity is zero; the velocity function equals
<span>(t-1)(t-7) a difference of squares so the zeros are 1 and 7, it changes direction at 1 second and 7 seconds. </span><span>
c) find the total distance traveled by the particle from t=0 and t=4
</span><span>s(0) = c
s(1) = 8/3 + c
s(4) = 64/3 - 64 + 28 + c.
</span>
from 0 to 1 the particle travels 8/3 units. From 1 to 4 it travels -(64/3 - 36 - 8/3) = (-(56/3 - 108/3))
<span>=-(-52/3) = 52/3 units
</span>
<span>so in total it travels 52/3 + 8/3 =20 units</span>
