Answer:
The change in kinetic energy is 4.3875 kJ
The amount of energy transferred by heat for the process is -66.98 kJ
Explanation:
Given;
mass of the system, m = 13 kg
change in height, Δh = -50 m
initial velocity, u = 15 m/s
final velocity, v = 30 m/s
change in internal energy per mass, ΔU = -5 kJ/kg
The change in kinetic energy is given by;
ΔK.E = K.E₂ - K.E₁
ΔK.E = ¹/₂mv² - ¹/₂mu²
ΔK.E = ¹/₂m(v² - u²)
ΔK.E = ¹/₂ ₓ 13 (30² - 15²)
ΔK.E = 4387.5 J
ΔK.E = 4.3875 kJ
The amount of energy transferred by heat for the process;
Q = W + ΔP.E + ΔK.E + ΔU
Where;
ΔP.E = mgΔh
ΔP.E = 13 x 9.8 x (-50)
ΔP.E = -6370 J = -6.37 kJ
W = 0
ΔU = -5kJ/kg x 13kg
ΔU = -65 kJ
Q = W + ΔP.E + ΔK.E + ΔU
Q = 0 + (-6.37) + (4.3875) + (-65)
Q = -66.98 kJ
Answer:
Velocity = 94.85m/s
Explanation:
<u>Given the following data ;</u>
Height = 1200m
Vertical distance = 1050m
To find the time, we would use the second equation of motion;

Substituting into the equation, we have;

t = 11.07 secs
To find the velocity;
Mathematically, velocity is given by the equation;

Substituting into the above equation;

Velocity = 94.85m/s
Therefore, the velocity of the water above 1050 m over the sea level is 94.85m/s.
Answer:
if it is at a speed of 12.5 m / s it would take 2 minutes
Explanation:
One radian per second is equal to 206265 seconds of arc. (On a plane angle)
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