Hydrogen fuel cells is the answer
Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
Answer:
The required new pressure is 775 mm hg.
Explanation:
We are given that gas has a volume of 185 ml and a pressure of 310 mm hg. The desired volume is 74.0 ml.
We have to find the required new pressure.
Let the required new pressure be '
'.
As we know that Boyle's law formula states that;

where,
= original pressure of gas in the container = 310 mm hg
= required new pressure
= volume of gas in the container = 185 ml
= desired new volume of the gas = 74 ml
So,
= 775 mm hg
Hence, the required new pressure is 775 mm hg.
Answer:
The possible range of wavelengths in air produced by the instrument is 7.62 m and 0.914 m respectively.
Explanation:
Given that,
The notes produced by a tuba range in frequency from approximately 45 Hz to 375 Hz.
The speed of sound in air is 343 m/s.
To find,
The wavelength range for the corresponding frequency.
Solution,
The speed of sound is given by the following relation as :

Wavelength for f = 45 Hz is,


Wavelength for f = 375 Hz is,


So, the possible range of wavelengths in air produced by the instrument is 7.62 m and 0.914 m respectively.