The time it takes "to complete one cycle" is a perfect definition for <em>period</em>.
So the <em>2 sec</em> that you measured is the swing's period.
Frequency is just 1/period (the 'reciprocal' of the period).
For this swing, the frequency is 1/(2sec) = 0.5 per second = <em>0.5 Hz</em>.
( "Hertz" means "per second")
Gymnasts often
practice on foam floors, which increase the collision time when a gymnast
falls. What effect does this have on collisions
The effect of the gymnast on the collision will increase.
An elastic collision is when two bodies collide and separates after collision
conserving the total kinetic energy before and after collision.
Answer:
The force of gravity after you double the mass and the distance is half of the initial force: 
Explanation:
The initial force of gravity is:

where
is the universal gravitational constant,
is the mass of the first object,
is the mass of the second object, and
is the distance between the objects.
If the mass of the second object is doubled, now we have
, and if the distance between the objects is also doubled instead of
now we have
.
So the force of gravity now is:

and we know that 
so the new force of gravity is:

The force of gravity after you double the mass and the distance is half of the initial force.
Answer:
turning lights of when you aren't using them
Answer:
<em>380 kHz</em>
<em></em>
Explanation:
The speed of sound is taken as 1500 m/s
The length of the fetus is 1.6 cm long
The condition is that the wavelength used must be at most 1/4 of the size of the object that is to be imaged.
For this 1.6 cm baby, the wavelength must not exceed
λ =
of 1.6 cm =
x 1.6 cm = 0.4 cm =
0.4 cm = 0.004 m this is the wavelength of the required ultrasonic sound.
we know that
v = λf
where v is the speed of a wave
λ is the wavelength of the wave
f is the frequency of the wave
f = v/λ
substituting values, we have
f = 1500/0.004 = 375000 Hz
==> 375000/1000 = 375 kHz ≅ <em>380 kHz</em>