- #1
gijungkim
- 50
- 2
Homework Statement
Carts A and B have equal masses and travel equal distances D on side-by-side straight frictionless tracks while a constant force F acts on A and a constant force 2F acts on B. Both carts start from rest. The velocities vA and vB of the bodies at the end of distance D are related by
a.vB = vA.
b.vB = vA.
c.vB = 2 vA.
d.vB = 4 vA.
e.vA = 2vB.
Homework Equations
F = ma
x = vot + 0.5 at^2
Vf = Vo + at
The Attempt at a Solution
Answer is B but I have no clue why
First, I just picked a random number to make it easier. I picked acceleration of 2m/s^2 for A and 4m/s^2 for B (since it has twice more force than A)
and I picked x as 1m
Then I'll get
1 = 0 + 0.5 * 2 * t^2, t = 1 for A
1 = 0 + 0.5 * 4 * t^2, t = 0.707 for B
If I plug this into Vf = V0 + at
Vf = 2 for A
Vf = 2.83 for B...
To me vB = vA doesn't make sense.. Can anyone help me