Answer: If one billiard ball hits another, the second will move with the same force as the first.
A child wants to jump to climb a tree (reaction), he must push the ground to propel himself (action).
A man deflates a balloon; the force with which the air comes out causes the balloon to move from one side to the other.
Explanation:
The equation relevant to this is:
S(t) = So + Vot - At²/2 <span>
</span>
<span>Therefore
we can create two equations:
<span>S(t) = 90 = So - 4t - 16.1t² -->
eqtn 1</span>
<span>S(t+2) = 10 = So - 4(t+2) - 16.1(t+2)² --> eqtn 2</span>
</span>
<span>Expanding
eqtn 2:
10 = So - 4t - 8 - 16.1(t² + 4t + 4)
10 = So - 4t - 8 - 16.1t² - 64.4t - 64.4
10 + 8 + 64.4 = So - 68.4t - 16.1t²
<span>82.4 = So - 68.4t - 16.1t² -->
eqtn 3</span></span>
<span>
Subtracting eqtn 1 by eqtn 3:</span>
90 = So - 4t - 16.1t²
82.4 = So - 68.4t - 16.1t²
=> 7.6 = 64.4t
t = 0.118 s
Therefore calculating for initial height So:<span>
<span>82.4 = So - 68.4(0.118) - 16.1(0.118)²
<span>So = 90.7 ft</span></span></span>
Answer:
C
Explanation:
Energy is neither created or destroyed, but it can change forms...
Let x mph be the speed of the ship in still water.
Against the current, the net speed is, (x-1.9) mph.
Time, t= distance, d/ Speed, v => 9= 113.4/(x-1.9) => 9(x-1.9) = 113.4 => x-1.9 = 113.4/9 => x = 12.6+1.9 = 14.5 mph
Moving with the current, the net speed of the ship = 14.5+1.9 =16.4 mph
Time take, t = d/v = 113.4/16.4 = 6.915 hours
