Answer:
<h3>The answer is 2.51 s</h3>
Explanation:
The time taken can be found by using the formula

d is the distance
v is the velocity
From the question we have

We have the final answer as
<h3>2.51 s</h3>
Hope this helps you
Answer:
A) The crossbeam is moving relative to the observer on the platform so the height appears contracted.
Explanation:
The observer on the train and the beam are in the same reference frame. That means observer on the train will measure the proper length of the beam not the contracted length . the observer is outside and the plank is in the moving system,it will appear to be moving.
If the container explodes there is no pressure, becuase all your gas has escaped its container, there for, you ain’t got no gas