Answer:
i would say that the answer would be B
Answer:
37.545 m/s
Explanation:
f' = Actual frequency of horn = 269 Hz
f = Observed frequency of horn = 290 Hz
v = Speed of sound in air = 343 m/s
= Speed of second train = 13.7 m/s
= Speed of first train
From Doppler effect we have

The speed of the first train is 37.545 m/s
The total resistance of an electric circuit with resistors widener series in the sum of the individual resistances:
Each resistor in a series circuit has a same amount of current flowing through it.
Each resistor in a parallel circuit has the same for voltage of the source applied to it.
When was this is are connected in parallel, the supply current is equal to the sum of the current through each resistor. In other words the currents in the branches of a parallel circuit add up to the supply current. When resistors are connected in parallel they have the same potential differences across them.
Compared with an Earth year, a galactic year represents time on a grand scale but its not a consistent measurement across the galaxy
Modern space suits augment the basic pressure garment with a complex system of equipment and environmental systems designed to keep the wearer comfortable, and to minimize the effort required to bend the limbs, resisting a soft pressure garment's natural tendency to stiffen against the vacuum. A self-contained oxygen supply and environmental control system is frequently employed to allow complete freedom of movement, independent of the spacecraft.
Three types of spacesuits exist for different purposes: IVA (intravehicular activity), EVA (extravehicular activity), and IEVA (intra/extravehicular activity). IVA suits are meant to be worn inside a pressurized spacecraft, and are therefore lighter and more comfortable. IEVA suits are meant for use inside and outside the spacecraft, such as the Gemini G4C suit. They include more protection from the harsh conditions of space, such as protection from micrometeorites and extreme temperature change. EVA suits, such as the EMU, are used outside spacecraft, for either planetary exploration or spacewalks. They must protect the wearer against all conditions of space, as well as provide mobility and functionality.