Answer:
6.86 meters
Explanation:
Let the compression of the string be represented by x, and the height of projection of the toy rocket be represented by h.
So that;
x = 9 cm = 0.09 m
In its rest position (i.e before the launch), the spring has a stored potential energy which is given as;
PE =
K
=
x 830 x 
= 415 x 0.0081
= 3.3615
The potential energy in the string = 3.36 Joules
Also,
PE = mgh
where: m is the mass, g is the gravitational force and h the height.
m = 50 g = 0.05 kg, g = 9.8 m
Thus,
PE = 0.05 x 9.8 x h
3.3615 = 0.05 x 9.8 x h
3.3615 = 0.49h
⇒ h = 
= 6.8602
The height of the toy rocket would be 6.86 meters.
Having said that,
mV + M0 = (m + M)v; where m = bullet mass, M = block mass, V = bullet velocity upon incoming, and v = the block and bullet velocity (ideal without losses) is the answer you are looking for. Thus, v = V(m/(m + M)) is what you want. m = Mb, M = Mw, and V = Vi.
If the wall doesn't move, its mean that <u>the work he did is 0 J</u>.
<h3>Introduction</h3>
Hello my friend ! Here, I will help you. Alright, before it, I will to introduce to you about work (physics). In the world of physics, <u>work is the amount of force exerted to cause an object to move a certain distance from its starting point</u>. The amount of work will be proportional to the increase in force and increase in displacement. Amount of work can be calculated by this equation :

With the following condition :
- W = work (J)
- F = force (N)
- s = shift or displacement (m)
<h3>Proof</h3>
How about a stationary object like a wall pushed by Mr. Avalos ? Yes it is 0 J. Let's prove it!
Give :
- F = force of Mr. Avalos = 150 N
- s = displacement of wall = 0 m
- t = interval of the time = 60 s
Asked : W = work = ... J
Proven :


(Q.E.D)
<h3>See More :</h3>
Answer:
0.1111 W/m²
Explanation:
If all other parameters are constant, sound intensity is inversely proportional to the square of the distance of the sound. That is,
I ∝ (1/r²)
I = k/r²
Since k can be the constant of proportionality. k = Ir²
We can write this relation as
I₁ × r₁² = I₂ × r₂²
I₁ = 0.25 W/m²
r₁ = 16 m
I₂ = ?
r₂ = 24 m
0.25 × 16² = I₂ × 24²
I₂ = (0.25 × 16²)/24²
I₂ = 0.1111 W/m²
As a consequence, gravity will accelerate a falling object so its velocity increases 9.81 m/s or 32 ft/sfor every second it experiences free fall. Velocity (v) can be calculated via v = gt, where g represents the acceleration due to gravity and t represents time in free fall.