I'm pretty sure that there should be an options to choose. Anyway, I've seen this question before and I know that this is an example of <span>the phi phenomenon.</span>
The vaccine ofcourse. They helped in making the vaccine.
You said "<span>A rocket's acceleration is 6.0 m/s2.".
That just means that its speed increases by 6 m/s every second.
Whenever you look at it, its speed is 6 m/s faster than it was
one second earlier.
If it starts out with zero speed, then its speed is 6 m/s after 1 second,
12 m/s after 2 seconds, 18 m/s after 3 seconds . . . etc.
How long does it take to reach 42 m/s ?
Well, how many times does it have to go 6 m/s FASTER
in order to build up to 42 m/s ?
That's just (42/6) = 7 times.
Writing it correctly, with the units and everything, it looks like this:
(42 m/s) / (6 m/s</span>²)
= (42/6) (m/s) / (m/s²)
= (42/6) (m/s · s²/m)
= 7 seconds
The total number of revolutions made by the wheel
is closest to is 28.2 revolutions. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.
I think the question meant to say net force on the box. Since force is a vector, the direction matters. 20N left is negated completely by the 50N right, which means the net force is 50N-20N to the right, 30N.