Which unit would you use to express the height of your desk?
1 answer:
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Answer:
The correct option is;
d) Parallel to the plane
Explanation:
The forces acting on the box of mass, m are;
Weight of the box acting an angle, θ, equal to the inclination of the plane to the perpendicular of the plane
Weight of the box acting along the plane = m×g×sin(θ)
The force of friction along the plane = μ×m×g×cos(θ)
The total force acting downward along the plane , = m×g×sin(θ) + μ×m×g×cos(θ)
The Force needed to pull the box up along the plane F = The total force acting downward along the plane
F = m×g×sin(θ) + μ×m×g×cos(θ) = m×g×(sin(θ) + μ×cos(θ))
When the force, Fₐ is applied vertically, the force acting along the plane = Fₐ×cos(θ)
When the force is applied perpendicular, the force acting along the plane = Fₐ×sin(θ)
When the force is applied horizontally, the force acting along the plane = Fₐ×cos(θ)
When the force is applied parallel to the plane, the force acting along the plane = Fₐ
Therefore, since Fₐ > Fₐ×cos(θ) and Fₐ > Fₐ×sin(θ), for acute angles, we have that the least force is required when the force is acting parallel to the plane.
Answer:
The anserrs to the question are
(a) The temperature would be 566.67 K and
(b) The pressure of the resulting air stream is 14 bar
Explanation:
Here the two streams of gases meet ad form a single stream
The steady-flow energy equation can be implemented at the mixing point of the to streams as follows
mₐhₐ₁ + mₙ hₙ₁ + Q° + W° = mₐhₐ₂ + mₙhₙ₂
Where the flow is adiabatic, we have
Q = 0 and W = 0 hence
mₐhₐ₁ + mₙ hₙ₁ = mₐhₐ₂ + mₙhₙ₂ where h = cp×T we have
mₐcpₐ×Tₐ + mₙcpₙ×Tₙ = mₐcpₐ×T + mₐcpₙ×T
Therefore the final temperature T is given by
for the same kind of gas cpₐ =cpₙ therefore
where mₐ and mₙ are mass flow rate
Therefore we have where Tₐ = = 900 K and Tₙ = 400 K and mₙ = 2mₐ gives
=
= 1700/3 = 566.67 K
From Dalton's law, the total pressure of a mixture of gases is equal to the sum of the partial pressures of the components of the mixture
Therefore the total pressure of the combined stream = pₐ + pₙ = p
= 12 bar + 2 bar = 14 bar
Stream pressure = 14 bar