Answer:
The power of force F is 115.2 W
Explanation:
Use following formula
Power = F x V
= F cos0
= (30) x 4/5
= 24N
Now Calculate V using following formula
V = + at
= 0
a = / m
a = 24N / 20 kg
a = 1.2m /
no place value in the formula of V
V = 0 + (1.2)(4)
V = 4.8 m/s
So,
Power = x V
Power = 24 x 4.8
Power = 115.2 W
Answer:
q=39.15 W/m²
Explanation:
We know that
Thermal resistance due to conductivity given as
R=L/KA
Thermal resistance due to heat transfer coefficient given as
R=1/hA
Total thermal resistance
Now by putting the values
We know that
Q=ΔT/R
So heat transfer per unit volume is 39.15 W/m²
q=39.15 W/m²
Answer:
18 kJ
Explanation:
Given:
Initial volume of air = 0.05 m³
Initial pressure = 60 kPa
Final volume = 0.2 m³
Final pressure = 180 kPa
Now,
the Work done by air will be calculated as:
Work Done = Average pressure × Change in volume
thus,
Average pressure = = 120 kPa
and,
Change in volume = Final volume - Initial Volume = 0.2 - 0.05 = 0.15 m³
Therefore,
the work done = 120 × 0.15 = 18 kJ