View Full Version : Need PHYSICS guru to show me how
Stephen09
Sep 17, 2008, 05:47 PM
If anyone reads this in the next hour or so and you can help with physics PLEASE RESPOND! THANKS! (ill tell you the problem when you respond)
Capuchin
Sep 17, 2008, 05:51 PM
Go for it..
ballengerb1
Sep 17, 2008, 05:54 PM
Stephen, you got a response in 4 minutes and now you are AWOL. Normally folks tell us their question and those qualified will respond. What grade are you in and where?
Stephen09
Sep 17, 2008, 06:12 PM
I'm a senior in physics
Stephen09
Sep 17, 2008, 06:15 PM
Thanks for the concern guys... here it is:
A descent vehicle landing on the moon has a vertical velocity toward the surface of the moon of 23.5m/s. At the same time, it has a horizontal velocity of 56m/s.
a) At what speed does the vehicle move along its descent path?
b) At what angle with the vertical is its path?
Capuchin
Sep 17, 2008, 06:29 PM
This is simple vector addition, which is basic trigonometry:
Just take your 2 vectors and use them as the 2 short sides of a right angled triangle. a) is the length of the hypotenuse and b) is the corresponding angle.
Stephen09
Sep 17, 2008, 06:35 PM
So for part B your saying to use a tangent formula or what?
Capuchin
Sep 17, 2008, 06:37 PM
so for part B your saying to use a tangent formula or what?
From doing it in my head, it looks like you'll need to use cos(x) = adj/hyp, but you should check that.
Stephen09
Sep 17, 2008, 06:41 PM
With the adjacent being 56?
Capuchin
Sep 17, 2008, 06:49 PM
with the adjacent being 56?
No, you want the angle to the vertical, so you want the vertical to be adjacent.
Stephen09
Sep 17, 2008, 07:13 PM
If that were so it would be cos(23.5/60) and that ends up being .99 degrees...
Capuchin
Sep 17, 2008, 07:15 PM
it would be cos(23.5/60)
No it wouldn't. How did you get that?
ddpatel
Sep 19, 2008, 11:10 AM
thanks for the concern guys... here it is:
a descent vehicle landing on the moon has a vertical velocity toward the surface of the moon of 23.5m/s. At the same time, it has a horizontal velocity of 56m/s.
a) At what speed does the vehicle move along its descent path?
b) At what angle with the vertical is its path? bbbb
Unknown008
Sep 20, 2008, 03:12 AM
Wait a sec. The vertical is 23.5 and horizontal is 56. I think that tangent rule applies?
Anyway, that's what I would have done, without using my answer from (a) to avoid errors carried forward.