Answer:
Impulse =14937.9 N
tangential force =14937.9 N
Explanation:
Given that
Mass of car m= 800 kg
initial velocity u=0
Final velocity v=390 km/hr
Final velocity v=108.3 m/s
So change in linear momentum P= m x v
P= 800 x 108.3
P=86640 kg.m/s
We know that impulse force F= P/t
So F= 86640/5.8 N
F=14937.9 N
Impulse force F= 14937.9 N
We know that
v=u + at
108.3 = 0 + a x 5.8
So tangential force F= m x a
F=18.66 x 800
F=14937.9 N
Answer:
The answer to the question is
The heat transferred in the process is -274.645 kJ
Explanation:
To solve the question, we list out the variables thus
R-134a = Tetrafluoroethane
Intitial Temperaturte t₁ = 100 °C
Initial pressure = 3.5 bar = 350 kPa
For closed system we have m₁ = m₂ = m
ΔU = m×(u₂ - u₁) = ₁Q₂ -₁W₂
For constant pressure process we have
Work done = W = = P×ΔV = P × (V₂ - V₁) = P×m×(v₂ - v₁)
From the tables we have
State 1 we have h₁ = (490.48 +489.52)/2 = 490 kJ/kg
State 2 gives h₂ = 206.75 + 0.75 × 194.57= 352.6775 kJ/kg
Therefore Q₁₂ = m×(u₂ - u₁) + W₁₂ = m × (u₂ - u₁) + P×m×(v₂ - v₁)
= m×(h₂ - h₁) = 2.0 kg × (352.6775 kJ/kg - 490 kJ/kg) =-274.645 kJ