00:01
We've got a model airplane that's in a circle like this.
00:05
My plane's going to draw it in green there.
00:08
There's a plane.
00:11
It's on a tension wire with an angle of 20 degrees.
00:20
Okay.
00:23
The length of the wire is 60 meters.
00:30
The mass is 0 .750 kilograms.
00:35
The speed is 35 meters per second.
00:46
The tension in the wire, okay, we're just supposed to figure out the tension in the wire.
00:56
Okay, so the force inward is going to be mv squared over r.
01:13
The force downward is going to be w, which is mg.
01:24
That needs to be counteracted by the tension in the wire.
01:29
So t in the horizontal direction, so that would be t cosine theta, needs to be f, which is mv squared over r.
01:59
But t -sign theta, huh? i guess maybe the wire would be above it.
02:32
So i can't actually see the diagram.
02:37
So let's believe that it's this.
02:48
So now t -sign theta is going to equal m -g.
02:57
So we need t.
03:02
Okay? we know m, we know g, we know v and r.
03:17
Huh? well, it would seem like we have too much information.
03:48
This is going to be l.
03:51
L.
03:54
So i'm going to say this is probably the better one to use...