<h3><u>Answer;</u></h3>
A. 4
<h3><u>Explanation;</u></h3>
- <em><u>The period of a wave or periodic time is the time taken for a complete oscillation to occur. </u></em>For example its is the time taken between two successive crests or troughs.
- <em><u>The beats or oscillation that occur in one second represents the frequency. Frequency is the number of complete oscillations or beats in one second in a wave.</u></em>
- Frequency, measured in Hertz is given by the reciprocal of the periodic time.
- Thus; <u><em>Frequency or beats per second = 1/(1/4) = 4</em></u>
- <u><em>Hence , 4 beats per second</em></u>
Answer:
860.6 years.
Explanation:
The parameters given are;
Initial detector activity = 370000 alpha decays per second
Final detector activity = 93000 alpha decays per second
Formula for time to change in activity is given by the following relation;
t₉₃₀₀₀ = 2.72 × 10¹⁰ seconds = 860.6 years.
The force between two objects is calculated through the equation,
F = Gm₁m₂/d²
where m₁ and m₂ are the masses of the objects. In this case, an unknown mass and Earth. d is the distance between them and G is universal gravitation constant.
In the second case, if the force is to become 2.5 times the original and all the variables are constant except d then,
2.5F = Gm₁m₂ / (D²)
D = 0.623d
Subsituting the known value of d,
D = 0.623(6.9 x 10^8) = <em>4.298 x 10^8 m</em>
Answer: The correct answer is zero work done.
Explanation:
Work is said to be done when the object moves through a distance when the force is applied to the object.
If the object does not move a distance even the force is exerted on the object then the work done is zero in this case.
Therefore, when the force is exerted even when no work is done then this is called zero work done.
Centrifugal force is not a real force.
When you move around a curve, there IS a real force pulling you
around the curve. Since your body wants to go straight, it feels as if
there's a force trying to pull you away from the curve. But there isn't.
That feeling of a force is greater when your speed around the curve
is greater, or when the curve is tighter, i.e. smaller radius.
