- #1
NoMeGusta
- 15
- 0
I just wanted a second check on this. This is a mortar fired at a mountain to cause an avalanche. What is xf and yf given:
Vi=300 m/s
theta= 55 degrees
t = 42 secs
so I found
Vxi= 300cos(55) = 172 m/s
Vyi= 300sin(55) = 245 m/s
Xf = Xi +Vxi*t + (1/2) ax*(t^2)
= 0 +172(45) + (1/2)(0)(45^2)
= 7227 m
= 7.23 X 10^3 (this was correct w/the book)
Now for Yf
Yf = Yi +Vyi*t + (1/2) ay*(t^2)
= 0 + 245(45) + (1/2) (-9.80)*(45^2)
= 11058 - 9922
= 1136
= 1.14 X 10^3 ... book says 1.68 X 10^3
What am I doing wrong to not get Yf correct? Thanks for the help.
Vi=300 m/s
theta= 55 degrees
t = 42 secs
so I found
Vxi= 300cos(55) = 172 m/s
Vyi= 300sin(55) = 245 m/s
Xf = Xi +Vxi*t + (1/2) ax*(t^2)
= 0 +172(45) + (1/2)(0)(45^2)
= 7227 m
= 7.23 X 10^3 (this was correct w/the book)
Now for Yf
Yf = Yi +Vyi*t + (1/2) ay*(t^2)
= 0 + 245(45) + (1/2) (-9.80)*(45^2)
= 11058 - 9922
= 1136
= 1.14 X 10^3 ... book says 1.68 X 10^3
What am I doing wrong to not get Yf correct? Thanks for the help.