Page 27 - Science Course 2 (Book 2)

Mo8-L3a: What is Newton’s Second Law of Motion?

Unbalanced forces can change an object’s velocity The direction of acceleration is the same as the
by changing the object’s direction. direction of the net force.

Another name for a change in velocity over time is Acceleration is expressed in meters per second
acceleration. squared (m/s²), mass in kilograms (kg), and force in
newtons (N).
Unbalanced forces make an object accelerate by
changing its speed, its direction, or both.

Circular Motion

Circular motion is any motion in which an object is
moving along a curved path.

In circular motion, a force that acts perpendicular
to the direction of motion, toward the center of the
curve, is centripetal force.
Newton’s Second Law of Motion

According to Newton’s second law of motion, the
acceleration of an object is equal to the net force
acting on the object divided by the object’s mass.

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Math Skills

Newton’s Second Law Equation

1. This is what you know: mass, force
m = 0.5 kg f = 10N or 10kg • m/s²

2. This is what you need to f nd: acceleration : a

3. Use this formula: a F
m
4. Substitutes: The values for F and m into the formula
and divide. 10N kg•m/s²
a = = = 20 m/s²
0.5kg kg

Answer: The acceleration of the ball is 20 m/s²

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