- #1
cereal turtle
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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 = 1/2mv2
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.