Newton’s Second Law of Motion
A. The net force on an object is equal to
the product of its acceleration and its mass.
B. Force = Mass x Acceleration (F = m a)
1. SI unit for acceleration is meters
per second per second (m/s2)
2. SI unit for mass is the kilogram. (kg)
3. SI unit for force is measured
in kg x m/s2
a. This unit is called the newton (N).
4. One newton equals the force required to accelerate
one kg of mass 1 m/s2.
a. 1N = 1 kg X 1 m/s2
EXAMPLE: What is the net force on
a 1000-kg elevator accelerating at 2 m/s2?
Equation:
F = ma
Plug in values
F = 1000 kg x 2 m/s2
Rearrange F = (1000 x 2) (kg x m/s2)
Compute value
F = 2000 (kg x m/s2)
Compute
unit F = 2000 N
