Explanation:
The center of gravity is near the grip and does not change during throw. "Throwing through the tip," a popular term of how to throw a javelin, means throwing through the grip or center of gravity. The center of pressure is the aerodynamic force of drag and lift on the javelin.
Average speed = distance / time
Average speed = 90 km / 0.5 hrs
Average speed = 180 km per hour
<span>436 km
The conversion factor between kilocalorie/hour and watts is 1.163 (1 kcal/hr = 1.163 watt). So let's convert the energy consumption of the bird from watts to kcal/hr
3.7 w / 1.163 w hr/kcal = 3.18 kcal /hr
1 gram of fat has 9 kcal, so the total number of kcals consumed will be 4 * 9 = 36.
So the bird can fly for 36/3.18 = 11.32 hours
The distance traveled will be
11.32 h * 3600 s/h * 10.7 m/s / 1000 m/km = 436 km</span>
The charge on the moving particle
From Carnot's theorem, for any engine working between these two temperatures:
efficiency <= (1-tc/th) * 100
Given: tc = 300k (from question assuming it is not 5300 as it seems)
For a, th = 900k, efficiency = (1-300/900) = 70%
For b, th = 500k, efficiency = (1-300/500) = 40%
For c, th = 375k, efficiency = (1-300/375) = 20%
Hence in case of a and b, efficiency claimed is lesser than efficiency calculated, which is valid case and in case of c, however efficiency claimed is greater which is invalid.
