Answer:
0.352 s
Explanation:
Let g = 9.81 m/s2. Then the speed of the block after it's fall down a time t (seconds) before the collision is:
(0)
Using the law of momentum conservation, the total momentum of the system after the collision must be same as before the collision. Let the upward be the positive direction:
(1)
where 
are the mass and speed of the bullet prior to the impact. 
is the mass of the block. v is the speed of the system after the impact. We will focus on v for the next part:
As the system raise and come to a momentarily halt on top of the building (speed at top 
), let the vertical distance travel be h (m). We have the following equation of motion
(2)
As h is the same vertical distance that the block has fallen before the collision, we can solve for h in term of t:
(3)
If we plug eq. (3) into (2):
(4)
And plug eq (4) and (0) into eq (1), with all the numbers:
Answer:
6.91 Hz
Explanation:
Volume of the cube
= (1.5 x 10⁻² )³m³
= 3.375 x 10⁻⁶ m³
mass of the cube
= 3.375 x 10⁻⁶ x 8920 ( 8.92 g / cm³ = 8920 kg/m³ )
m = 30.105 x 10⁻³ kg
Spring stretches by 2.65 x 10⁻² m due to a force of 1.5 N.
If k be the force constant
k x = F
K x2.65 x 10⁻² = 1.5
k = .566 x 10² N / m
Now frequency of oscillation for spring - mass system is given by
n = 
=
n = 6.91 Hz
<u>Answer</u>
5.9 × 10¹⁴ Hz
<u>Explanation</u>
The wave equation states that;
V = λf
Where V ⇒ velocity of light
λ ⇒ wavelength
f ⇒ frequency
V = λf
3.0×10⁸ = 510×10⁻⁹ × f
Dividing both sides by 510×10⁻⁹,
f = (3.0×10⁸) / (510×10⁻⁹)
= 5.8824 × 10¹⁴ Hz
Answer to the nearest tenth, 5.9 × 10¹⁴ Hz.
An image that cannot be obtained on a screen is called an Virtual Image.
<span>The waves with the lowest energy and lowest frequencies of the electromagnetic spectrum are the "Radio waves"
So, option B is your answer
Hope this helps!
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