Projectile question - X and Y direction


by anthony123456
Tags: direction, projectile
anthony123456
anthony123456 is offline
#1
Apr5-12, 08:13 PM
P: 7
A bullet is fired at an angle of 60 with an initial velocity of 200 m/s. How long is the bullet in the air?


2. Relevant equations

Vix = Vicosθ
Viy = Visinθ

Vfy = Viy + ayΔt
Xf = xi + VixΔt

... Ask for more equations available....
3. The attempt at a solution

Vix = 200cos60 = 100m/s
Viy = 200sin60 = 173.2 m/s

X variables:
xi = 0m
xf = ?
Δt =?
Vix = 100m/s


Y variables:
Yi = ?
Yf = 0m
Δt =?
Viy = 173.2m/s
Vfy = ?
a = -9.8m/s


ANSWER HAS TO EQUAL 35.4 SECONDS, ACCORDING TO MY PHYSICS TEACHER!
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azizlwl
azizlwl is offline
#2
Apr5-12, 08:23 PM
P: 961
Relevant Equation
[itex]Y=(V_{iy})t-\frac{1}{2}at^2[/itex]
RoshanBBQ
RoshanBBQ is offline
#3
Apr5-12, 08:27 PM
P: 280
The question is unanswerable, because you are not given knowledge about the initial y-component position of the bullet or the landscape into which the bullet will travel.

But if we assume your teacher meant to describe a world in which bullets are fired from ground level into landscapes that are perfectly flat, we can proceed. If that is the case, Yi = 0. If you need additional help, just ask for it.


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