Explanation:
1st- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
2nd- states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. (most important law)
3rd- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. (law of action/reaction)
Answer:
a) variation of the energy is equal to the work of the friction force
b) W = Em_{f} -Em₀
, c) he conservation of mechanical energy
Explanation:
a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.
Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.
b) the calluses that he would use are to hinder the worker's friction force and energy
W = Em_{f} -Em₀
N d = ½ m v² - m g (y₂-y₁)
y₂-y₁ = 35 -10 = 25m
c) if there is no friction, the physical principle is the conservation of mechanical energy
If there is friction, the principle is that the non-conservative work is equal to the variation of the energy
Given Information:
Power of bulb = w = 25 W
atts
distance = d = 9.5 cm = 0.095 m
Required Information:
Radiation Pressure = ?
Answer:
Radiation Pressure =7.34x10⁻⁷ N/m²
Explanation:
We know that radiation pressure is given by
P = I/c
Where I is the intensity of radiation and is given by
I = w/4πd²
Where w is the power of the bulb in watts and d is the distance from the center of the bulb.
So the radiation pressure becomes
P = w/c4πd²
Where c = 3x10⁸ m/s is the speed of light
P = 25/(3x10⁸*4*π*0.095²)
P = 7.34x10⁻⁷ N/m²
Therefore, the radiation pressure due to a 25 W bulb at a distance of 9.5 cm from the center of the bulb is 7.34x10⁻⁷ N/m²
Answer:
a) 316880878140.2895 Joules
b) 1056.26 Joules
c) 372.80103310622 km²
Explanation:
Energy consumption
Average rate of electrical energy consumption is 316880878140.2895 Joules
Total population = 300 million
Each person consumes 1056.26 Joules.
Efficiency = 0.85
Power from Sun
Area
Converting to km²
Area required to collect the electrical energy used in the United States is 372.80103310622 km²
Answer:
v₀ = 292.3 m / s
Explanation:
Let's analyze the situation, on the one hand we have the shock between the bullet and the block that we can work with at the moment and another part where the assembly (bullet + block) compresses a spring, which we can work with mechanical energy, as the data they give us are Let's start with this second part.
We write the mechanical energy when the shock has passed the bodies
Em₀ = K = ½ (m + M) v²
We write the mechanical energy when the spring is in maximum compression
= 
= ½ k x²
Em₀ =
½ (m + M) v² = ½ k x²
Let's calculate the system speed
v = √ [k x² / (m + M)]
v = √[154 0.83² / (0.012 +0.104)
]
v = 30.24 m / s
This is the speed of the bullet + Block system
Now let's use the moment to solve the shock
Before the crash
p₀ = m v₀
After the crash
= (m + M) v
The system is formed by the bullet and block assembly, so the forces during the crash are internal and the moment is preserved
p₀ =
m v₀ = (m + M) v
v₀ = v (m + M) / m
let's calculate
v₀ = 30.24 (0.012 +0.104) /0.012
v₀ = 292.3 m / s
