Answer:
The speed of the car when load is dropped in it is 17.19 m/s.
Explanation:
It is given that,
Mass of the railroad car, m₁ = 16000 kg
Speed of the railroad car, v₁ = 23 m/s
Mass of additional load, m₂ = 5400 kg
The additional load is dropped onto the car. Let v will be its speed. On applying the conservation of momentum as :



v = 17.19 m/s
So, the speed of the car when load is dropped in it is 17.19 m/s. Hence, this is the required solution.
A neuron has a resting potential of about 70mV (millivolts)
Answer:
d = 1.07 mile
Explanation:
The rationale for this method is that the speed of light is much greater than the speed of sound, the definition of speed in uniform motion is
v = d / t
d = v t
the speed of sound is worth
v = 343 m / s
Therefore, the speed of sound must be multiplied by time to do this, all the units must be in the same system, as the distance in miles is requested
v = 343 m/s (1mile/1609 m) (3600s/1 h) = 343 (2.24) = 767.4 mile/h
v = 343 m / s (1 mile / 1609 m) = 0.213, mile/ s
If the measured time is t = 5s we multiply it by the speed
we substitute
d = 0.213 5
d = 1.07 mile
If you want to calculate the speed, this method in general is not widely used, since you must know the distance where the lightning occurred, which is relatively complicated.