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.
Explanation:
Your body uses chemical energy every day to perform daily tasks. Food contains calories and when you digest food, the energy is released. The molecules in food are broken down into smaller pieces. As the bonds between the atoms break or loosen, oxidation occurs.The chemical reaction involved in digestion supplies you with warmth, helps to maintain and repair your body and gives you the energy you need to move around.
Time and velocity are both vectors T/F
We have to use the equation speed=distance/time.
We want the average speed in second so we have to change the minutes into seconds. We can do this by multiplying the minutes by 60 (60seconds in 1 minute). 60x1.4= 84 seconds.
Speed=distance/time, distance is 82 and time is 84 so speed=82/84
Average speed = 0.98ms^-1 (2dp)
Going upstream against the current gives a net speed equivalent to the speed at still water minus the speed of the current. Consequently, the speed downstream gives a net speed equal to the speed at still water plus the speed of the current, making it travel faster. The solution is:
UPSTREAM
v = 20 - 1.5 = 18.5 km/h
t = 30 mins or 0.5 hours
distance = 18.5km/h (0.5 h) = 9.25 km
DOWNSTREAM
for the same distance of 9.25 km:
v = 20 + 1.5 = 21.5 km/h
t = 9.25km / 21.5 km/h = 0.43 hours or 25.8 mins = 26 mins --> FINAL ANS.