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
The correct answer is: Velocity
Well so we know that 11mm is 2440km so 1mm is 2440/11 which is 221.8.
Ans we know that Neptune is the farthest and the distance is 4.498 billion km the we would divide that by 221.8 to get answer.
Ans=2.36km
Answer:
Efficiency of the machine = 75%
Explanation:
Given:
Input work = 8,000 J
Output work = 6,000 J
Find:
Efficiency of the machine
Computation:
Efficiency of the machine = [Output work / Input work]100
Efficiency of the machine = [6,000 / 8,000]100
Efficiency of the machine = 75%
Answer: 37.5 km
Explanation:
The question is that
If you ran 15 km/hr for 2.5 hours, how much distance would you cover ?
Where
Speed = 15 km/ hr
Time = 2.5 hours
Using the formula for speed.
Speed = distance/time
Substitute speed and time into the formula
15 = distance/ 2.5
Make distance the subject of formula by cross multiplying.
Distance = 15 × 2.5
Distance = 37.5 km.