Answer:
1. F = 45,458.17 N
2. P = 12,800,000 W
Explanation:
Part 1. The thrust force is the sum of the forces on the air and on the fuel.
For the air, 107 kg of air is accelerated from 281 m/s to 679 m/s in 1 second.
F = ma
F = (107 kg) (679 m/s − 281 m/s) / (1 s)
F = 42,586 N
For the fuel, 4.23 kg of fuel is accelerated from 0 m/s to 679 m/s in 1 second.
F = ma
F = (4.23 kg) (679 m/s − 0 m/s) / (1 s)
F = 2,872.17 N
So the thrust on the jet is:
F = 42,586 N + 2,872.17 N
F = 45,458.17 N
Rounded to three significant figures, the force is 45,500 N.
Part 2. Power = work / time, and work = force × distance, so:
Power = force × distance / time
Power = force × velocity
P = (45,458.17 N) (281 m/s)
P = 12,773,745.77 W
Rounded to three significant figures, the power is 12,800,000 W.
Answer:
1.8 J
Explanation:
I had this exact question today and found someone who had solved it before, this was their response to the work done by gravity. They used the name "physicsmom"
Vertical distance = 1.8 sin 30 = .9 m
W = 2 N * .9 m = 1.8J
Good luck! I hope this helps!
Answer:
0 N, 3.49 m/s
Explanation:
Draw a free body diagram for the bucket at the top of the swing. There are two forces acting on the bucket: weight and tension, both downwards.
If we take the sum of the forces in the radial direction, where towards the center is positive:
∑F = ma
W + T = m v² / r
The higher the velocity that Rony swings the bucket, the more tension there will be. The slowest he can swing it is when the tension is 0.
W = m v² / r
mg = m v² / r
g = v² / r
v = √(gr)
Given that r = 1.24 m:
v = √(9.8 m/s² × 1.24 m)
v = 3.49 m/s
