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.
Answer:
2.5 m/s²
Explanation:
Using the formula, v = u + at ( v = Final velocity; u = Initial velocity; t = Time; a = Acceleration)
25 = 0 + 10a
a = 25/10 = 2.5 m/s²
<span>D. Atoms of all elements contain protons, but the number of protons is different for every element.
</span>
The answer is <span>d. the sun</span>
