Physics HW

[Xylitol]

Yea.. I need some help
Can soemoen solve this problem
My brain's dead righ tnow

How far does a plane fly in 15 s while its velocity is changing from 141 m/s to 78 m/s at a uniform rate of acceleration?

______ [m]

Thx

 

[ucdbiendog]

a = (v2-v1)/t

then use the kinematic equations to find distance, i dont remember them off the top of my head, but there are 3. your known values are v1, v2, a, and t. ue the one that has distance as an unknown, and the rest of the variables the ones that u already know

 

[MrCodeDude]

Vf = Vi + at
78 = 141 + 15a
-63 = 15a
a = -4.2 m/s^2

Sf = Si + Vit + 1/2a*t^2

Sf = 0 + 141 * 15 + .5 * -4.2 * 15^2
Sf = 2115 - 472.5
Sf = 1642.5m

 

[MrCodeDude]

Gah, I solve it for him and get no thanks. 🙁

 

[Ready]

The answer is 5

 

[ucdbiendog]

Originally posted by: MrCodeDude
Gah, I solve it for him and get no thanks. 🙁

thats what you get. you shouldnt do it for him, just tell him how to get started.