Download Forces in One Direction

Newton’s Second Law
Review
• From our introduction we learned that forces
are a push or pull in a particular direction.
– Therefore velocity is affected
– Therefore acceleration is affected
• Forces can be calculated and this is
accomplished with Newton’s Second Law.
Newton’s Second Law
• The acceleration of an object is directly
proportional to the net force acting on the
object, is in the direction of the net force, and
is inversely proportional to the mass of the
object.
• a = F/m
• This can be rearranged to solve for forces.
Yay!
• Despite the fact that this equation is almost
500 years old, it is still one of the most
powerful equations we know.
• A force is a push or a pull. It may be
gravitational, electrical/magnetic, nuclear or
simple muscular effort.
How do we use it?
• In honor of the man who codified it, the units
for forces are Newtons.
• What is a newton?
• F = ma
– Mass units are kg
– Acceleration units are m/s2
– Therefore Newtons are equivilent to (kg · m)/s2
Forces are Vectors
Circle the right answer
1.
The forces shown above are pushing/pulling forces.
2.
The forces shown above are working together/opposite forces.
3.
The forces are equal/not equal.
4.
The forces do/do not balance each other out.
5.
The resulting force is 1000 N to the left/1000 N to the right/ Zero N.