Parametric equations -> acceleration

[burton95]

parametric equations --> acceleration

Homework Statement

An object is moving at constant acceleration in the x-y plane. Its position and velocity at two different times are given by the following equations:
What is the magnitude of the object’s acceleration (in m/s2) as it moves from the first position to the second position? Hint: solve for the acceleration along each axis separately.

Homework Equations

r₁= (2m)i + (4m)j
r₂= (10m)i + (14m)j

v₁= (1m/s)i + (8m/s)j
v₂= (7m/s)i + (2m/s)j

The Attempt at a Solution

I decided to calc magnitude of the velocity

$\left\|$v1$\right\|$ = (8²+1²)^1/2 = 8.06

mag v2 = (7² + 2²)^1/2 = 7.2801

(Vf)²=(Vi)² + 2asΔs

for y
(7.2801)²=(8.06)²+2as(10)
as = -.7457725

for x
(7.2801)²=(8.06)²+2as(8)
as = -.59818

√((-.59818²)+(-.7457725²) = .95755

 

[rude man]

I would follow your instructor's hint and work with one coordinate at a time. Your eq's. don't make sense to me.

BTW I think you have to assume constant acceleration in this problem.

You might try the following:

1. write eq. for v_x(t).
2. write eq. for x(t).

Eq's. 1 and 2 give you a_x and T, the time of transit from r1 to r2.
3. do same for y.