Answer:
Explanation:
Efficiency of a Carnot engine = 1 – (T2/T1)
;
where T1 = source temperature and T2 = sink temperature
T2 = 10⁰C = 273+10 = 283K
The initial efficiency = 40%
So 0.4 = 1 - (283/Initial T1)
Initial T1 = 283/(1-0.4) = 471.67 K
To raise efficiency to 65%
0.65 = 1 - (283/Increased T1)
Increased T1 = 283/(1-0.65) = 808.57 K
The source temperature must be increased by 808.57 - 471.67 = 336.9 K or 336.9°C.
Answer:
x ’= 368.61 m, y ’= 258.11 m
Explanation:
To solve this problem we must find the projections of the point on the new vectors of the rotated system θ = 35º
x’= R cos 35
y’= R sin 35
The modulus vector can be found using the Pythagorean theorem
R² = x² + y²
R = 450 m
we calculate
x ’= 450 cos 35
x ’= 368.61 m
y ’= 450 sin 35
y ’= 258.11 m
Answer:
A professional basketball game depends on the association presiding over the game. An NBA game lasts for 48 minutes whereas FIBA games take 40 minutes. The total time taken to play for any specialized game is over 2 hours 15 minutes. The time includes the time disruptions like fouls, timeouts, and breaks.
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Answer:
120°
Explanation:
Draw a free body diagram. There are three forces acting on the traffic light. Two tension forces acting along the cables, and weight.
The tension forces have an angle θ between them. That means each tension force forms an angle of θ/2 with respect to the vertical. So the y component of each tension force is:
Ty = T cos (θ/2)
Sum of the forces in the y direction:
∑F = ma
Ty + Ty − W = 0
2 Ty = W
Substituting:
2 T cos (θ/2) = W
If W = T, then:
2 W cos (θ/2) = W
2 cos (θ/2) = 1
cos (θ/2) = 1/2
θ/2 = 60°
θ = 120°
