- #1

cereal turtle

- 2

- 0

## Homework Statement

If the resultant force acting on a 2.0kg object is equal to (3i + 4j) N, what is the change in kinetic energy as the object moves from (7i -8j)m to (11i -5j)m

## Homework Equations

w = Fd

Ek = 1/2mv

^{2}

## The Attempt at a Solution

I assumed that Ek = w so I tried to solve it by getting the change in displacement and then getting the dot product using the given force (did not use the mass at all)

d= (11i -5j) - (7i -8j)

= (4i +3j)

w= (3i +4j)(4i + 3j)

= (12i + 12j)

|w| = 17 J

... this answer was totally wrong, as the answer should be 24 J.

I can't really grasp the relationship with force and kinetic energy.. would appreciate some help. thank you.