Unbalanced forces
When the forces acting on an object do not balance, the resultant force will cause the object to accelerate in the direction of the resultant force.
In other words, a resultant force on a body will cause it to change its velocity. This simply means that unbalanced forces will cause:
acceleration
deceleration
change in direction. The relationship between the resultant force, the mass of the object and the object’s acceleration is:
resultant force (N)
=
mass (kg)
×
acceleration (m/s
2
)
F
=
m
×
a
You will have to be able to state this equation in the examination.
Question
A car weighs 1,000 kg. The resultant force is 5,000 N. Use the Fma triangle to find the acceleration of the car.