If the resultant force acting on a 2kg 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?

Answer 1

get x motion vector
(11i-5j) - (7i+8j) = 4 i + 3 j

F dot x = (3 i + 4 j) dot ( 4 i + 3 j )
= 12 + 12 = 24 Joules work done
= change in kinetic energy

Answer 2

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

Answer 3

|F|=√(3)²+(4)²
=5N

|m|=√(3)²+(4)²
=5m

W=F∆xcos¶
=5(5)cos(0)
=25J

Answer 4

The work done by the resultant force in moving the object from (7i -8j) m to (11i -5j) m is 25 J (Joules).

As per the work-energy principle, the work done by all forces acting on an object is equal to the change in kinetic energy of the object. Therefore, the change in kinetic energy of the 2.0kg object is also 25 J.