Answer:
Therefore maximum stretch is y2 = 32.36 m
Explanation:
In this problem let's use the initial data to find the string constant, let's apply Newton's second law when in equilibrium
- W = 0
k Δx = mg
k = mg / Δx
k = 80 9.8 / (30-20)
k = 78.4 N / m
now let's use conservation of energy to find the velocity of the body just as the string starts to stretch y = 20 m
starting point. When will you jump
Em₀ = U = mg y
final point. Just when the rope starts to stretch
= K = ½ m v²
Em₀ = Em_{f}
mg y = ½ m v²
v = √ 2g y
v = √ (2 9.8 20)
v = 19.8 m / s
now all kinetic energy is transformed into elastic energy
starting point
Em₀ = K = ½ m v²
final point
Em_{f} = 
+ U = ½ k y² + m g y
Emo = Em_{f}
½ m v² = ½ k y² + mgy
k y² + 2 m g y - m v² = 0
we substitute the values and solve the quadratic equation
78.4 y² + 2 80 9.8 y - 80 19.8² = 0
78.4 y² + 1568 y - 31363.2 = 0
y² + 20 y - 400 = 0
y = [- 20 ±√ (20 2 +4 400)] / 2
y = [-20 ± 44.72] / 2
the solutions are
y₁ = 12.36 m
y₂ = 32.36 m
These solutions correspond to the maximum stretch and its rebound.
Therefore maximum stretch is y2 = 32.36 m
Answer:
Option 3 is the correct option to the following question.
Explanation:
Double slit experiment:
The double-slit experiment in modern physics reveals that light and matter can exhibit characteristics of both classically described waves and particles; it also shows the inherently probabilistic existence of quantum mechanical phenomena.
When two wavelength meets ,if the resultant amplitude is maximum then this is known as constructive interference and the resultant amplitude is maximum then this is known as destructive interference.
Therefore the answer is "3".
Given that the potential difference is V = 1.5 V.
The length of the wire is l = 1.5 m.
The cross-sectional area is
The resistivity of the wire is
We have to find the power dissipated in the wire.
First, we need to calculate resistance.
The resistance can be calculated as
The formula to calculate power is
Substituting the values, the power will be
Thus, the power dissipated in the wire is 17.1 W
Answer:
Scale reading for no wind 
Explanation:
From the question we are told that
Area 
Weight of board 
Velocity 
Density of air 
Generally the equation for pressure difference by Bernoulli equation is mathematically given by
Generally force acting on the board by air is mathematically given by
Therefore
Scale reading for no wind W'
Scale reading for no wind W'=60N
Answer:
12 (Magnesium- Mg)
Explanation:
Looking at the four numbers, we have:
Magnesium, Silicon, Sulfur, and Chlorine.
We can eliminate two of the answers immediately just by looking at the periodic table.
Sulfur and Chlorine are on the nonmetal side of the periodic table. So that's <em>definitely</em> not it. That leaves Magnesium and Silicon.
Silicon is a Metalloid. Magnesium is an Alkaline earth Metal.
Metaloids are elements that have a mix of both<em> metal</em> and<em> nonmetal </em>properties (luster, how it feels, etc.). Since it's a MIX and Magnesium is just straight METAL-
We can say Magnesium has the most metallic properties.
hope this helps!!
