- #1
riken9
- 10
- 0
Homework Statement
1. At t = 0, a particle leaves the origin with a velocity of 9.0 m/s in the positive y direction and moves in the xy plane with a constant acceleration of (2.0i - 4.0j) m/s2. At the instant the x coordinate of the particle is 15 m, what is the speed of the particle?
2. A particle starts from the origin at t = 0 with a velocity of 6.0 m/s and moves in the xy plane with a constant acceleration of (-2.0 + 4.0 ) m/s2. At the instant the particle achieves its maximum positive x coordinate, how far is it from the origin?
Homework Equations
rf = ri + vt + 1/2at^2
vf = vi + at
The Attempt at a Solution
1. rf = ri + vt + 1/2at^2
t = 2.25 [seconds]
vf = (9j) + [2i - 4j)t
Sub t into there and i get 4 m/s But the answer is: 10 m/s
2. v(initial)=6i m/s
v(final)=?
a= (-2i + 4j) m/s^2
starts at coordinate (0,0)
need to find max x point
rf = 6i + [-1i + 2j]t^2
vf = vi + at
How do i find t if i don't have final velocity? Answer is: 20m.