Answer:
about 14.7°
Explanation:
The formula for the angle of the first minimum is ...
sin(θ) = λ/a
where θ is the angle relative to the door centerline, λ is the wavelength of the sound, and "a" is the width of the door.
The wavelength of the sound is the speed of sound divided by the frequency:
λ = (340 m/s)/(1300 Hz) ≈ 0.261538 m
Then the angle of interest is ...
θ = arcsin(0.261538/1.03) ≈ 14.7°
At an angle of about 14.7°, someone outside the room will hear no sound.
The car should have a velocity of 60 m/s to attain the same momentum as that of the truck of 2000 kg.
Answer:
Explanation:
Momentum is measured as the product of mass of object with the velocity attained by that object.
Momentum of 2000 kg truck = Mass × Velocity
Momentum of 2000 kg truck = 2000×30 = 60000 N
Similarly, the momentum of 1000 kg car will be 1000× velocity of the 1000 kg car.
Since, it is stated that momentum of 2000 kg truck is equal to the momentum of 1000 kg of car, then the velocity of 1000 kg of car can be determined by equating the momentum of car and truck.
Momentum of 2000 kg truck = Momentum of 1000 kg car
60000=1000×velocity of 1000 kg car
Velocity of 1000 kg car = 60000/1000=60 m/s
So, the car should have a velocity of 60 m/s to attain the same momentum as that of the truck of 2000 kg.
The mass of water that must be raised is 
Explanation:
Since the process is 70% efficiency, the power in output to the turbine can be written as

where
is the power in input.
The power in input can be written as

where
W is the work done in lifting the water
t = 3 h = 10,800 s is the time elapsed
The work done in lifting the water is given by

where
m is the mass of water
is the acceleration of gravity
h = 45 m is the height at which the water is lifted
Combining the three equations together, we get:

Where

And solving for m, we find:

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About 12 hours is the time between a morning high tide and the next high tide
Explanation:
The Earth’s rotation happens between two tidal bulges
The “periodic rise and fall” of the surface water levels of the ocean is called tides. The gravitational action and interaction on the earth by the sun and the moon causes these tides. Different regions of the World experiences different patterns of tides like the diurnal, semi-diurnal etc.
When there is one high and one low tide occurring on a lunar day, then it is diurnal pattern. Semi-diurnal pattern occurs when there are two equal high and low tides on a single lunar day.
Since the Earth’s rotation happens between two tidal “bulges” on each lunar day, the coastal areas can experience two high and two low tides in every 24 hours plus 50 minutes.
Accordingly the time between two high tides would be 12 hours plus 25 minutes. Similarly, the time gap between a high to low tide would be 6 hours plus 12.5 minutes.
The correct answer for the question that is being presented above is this one: "c. transition state stage." During the transition state stage, the reaction of the atoms have the highest energy. It is also <span>during the formation of the activated complex in the middle of the experiment.</span>