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:
may be upside down alphabet :"T"
Explanation:
Answer:
Length = 2.92 m
Diameter = 0.11 mm
Explanation:
We have
, where:
is the length

We divide the first equation by the second equation to get:


Using this Area, we find the diameter of the wire:



To find the length, we multiply the two equations stated initially:


Answer:
quark
Explanation:
neutrón= 1.675 x 10-27 kg
proton=1,673 x 10-27 kg
electron=9,11 x 10-31 kg
quark=7,13 - 14,26 · 10−30 kg