same but who knows how 2021 might go
Answer:

Explanation:
As we know that train is initially moving with the speed

now we know that

now the final speed of the train when it crossed the crossing


now we can use kinematics here



Now the time to cross that junction is given as



Answer:
m = 3.91 kg
Explanation:
Given that,
Mass of the object, m = 3.74 kg
Stretching in the spring, x = 0.0161 m
The frequency of vibration, f = 3.84 Hz
When the object is suspended, the gravitational force is balanced by the spring force as :



k = 2276.52 N/m
The frequency of vibration is given by :



m = 3.91 kg
So, the mass of the object is 3.91 kg. Hence, this is the required solution.
The right answer is
all of the above
good luck