Answer:
D
Explanation:
It's quite simple actually, you see, what light years basically means is how many years light takes to travel from point a to point b. So here it says that a galaxy is 200 million light years away. So since that light is 200 million years away, it would take 200 million years until that light reaches us.
Answer:
En el deporte, la persona que lo práctica tiene que adecuarse a él, por el contrario cuando hablamos de actividad física el objetivo pasa por programar, dosificar y adecuar en entrenamiento a las características, necesidades y objetivos de cada persona.
Explanation:
They probably put "rolls without slipping" in there to indicate that there is no loss in friction; or that the friction is constant throughout the movement of the disk. So it's more of a contingency part of the explanation of the problem.
(Remember how earlier on in Physics lessons, we see "ignore friction" written into problems; it just removes the "What about [ ]?" question for anyone who might ask.)
In this case, you can't ignore friction because the disk wouldn't roll without it.
As far as friction producing a torque... I would say that friction is a result of the torque in this case. And because the point of contact is, presumably, the ground, the friction is tangential to the disk. Meaning the friction is linear and has no angular component.
(You could probably argue that by Newton's 3rd Law there should be some opposing torque, but I think that's outside of the scope of this problem.)
Hopefully this helps clear up the misunderstanding for you.
Answer:
Explanation:
Time period, T = 50 μs = 50 x 10^-6 s
Frequency is defined as the number of oscillations or vibrations completed in one second.
The reciprocal of time period is called frequency.
f = 1 / T
f = 1 / (50 x 10^-6)
f = 20,000 Hz
Angular frequency, ω = 2 x π x f
ω = 2 x 3.14 x 20,000
ω = 125600 rad/s
