atoms of lithium, sodium,
and potassium almost never found alone in nature because t<span>hey have only one electron in their outer most
shell which makes them very reactive and they react with other atoms thats why.
I hope this can help you</span>
Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height
To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height
So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point
Solving the quadratic equation
So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:
Since the projectile is going down the velocity at the instant it reaches the ground is:
Answer:
r = 4.44 m
Explanation:
For this exercise we use the Archimedes principle, which states that the buoyant force is equal to the weight of the dislodged fluid
B = ρ g V
Now let's use Newton's equilibrium relationship
B - W = 0
B = W
The weight of the system is the weight of the man and his accessories (W₁) plus the material weight of the ball (W)
σ = W / A
W = σ A
The area of a sphere is
A = 4π r²
W = W₁ + σ 4π r²
The volume of a sphere is
V = 4/3 π r³
Let's replace
ρ g 4/3 π r³ = W₁ + σ 4π r²
If we use the ideal gas equation
P V = n RT
P = ρ RT
ρ = P / RT
P / RT g 4/3 π r³ - σ 4 π r² = W₁
r² 4π (P/3RT r - σ) = W₁
Let's replace the values
r² 4π (1.01 10⁵ / (3 8.314 (70 + 273)) r - 0.060) = 13000
r² (11.81 r -0.060) = 13000 / 4pi
r² (11.81 r - 0.060) = 1034.51
As the independent term is very small we can despise it, to find the solution
r = 4.44 m
Answer:
Convection occurs when thermal energy is transferred by the movement of fluid particles.
Explanation:
Transfer of heat energy by the movement of fluid particles is called convection. Convection takes place in liquids and gases due to kinetic energy. When heat is provided to liquids and gases they expand and move faster.
Molecules with higher kinetic energy become less dense and rise up to the surface of liquid, whereas molecules with lower energy move towards the bottom. This up and down movement of molecules causes convection currents in fluids.
