The first law of thermodynamics is expresses by
D. ΔU=Q-W
which means change in internal energy of system = Heat added to system minus work done by the system
All are expressed in Joules.
This law is based on principle of conservation of energy.
Answer:
b) 20 kJ
Explanation:
Efficiency of carnot engine = (T₁ - T₂ ) / T₁ Where T₁ is temperature of hot source and T₂ is temperature of sink .
T₁ = 270 + 273 = 543K
T₂ = 50 + 273 = 323 K
Putting the given values of temperatures
efficiency = (543 - 323) / 543
= .405
heat input = 50 KJ
efficiency = output work / input heat energy
.405 = output work / 50
output work = 20.25 KJ.
= 20 KJ .
We have that the maximum rank of the kangaroo is given by:
R = v0 ^ 2 sin (2θ) / g
where,
v0 = initial velocity
θ = angle of the velocity vector formed from the horizontal
g = gravity
Clearing the speed we have:
v0 ^ 2 = (R * g) / (sin (2θ))
Substituting values
v0 = root (((11) * (9.8)) / (sin (2 (21 * (pi / 180)))))
v0 = 12.69 m / s
answer
its takeoff speed is 12.69 m / s
Any key words? That they put there
