Acceleration is defined as the rate of change of an object's velocity. An object accelerates when its speed changes, its direction changes, or both change. Positive acceleration occurs when speed increases, while negative acceleration occurs when speed decreases. Even if speed stays the same, an object accelerates when its direction changes, such as when rounding a curve.

1. ACCELERATION
• Acceleration is a vector quantity that is defined
as the rate at which an object changes its
velocity.

2. ACCELERATION
An object is accelerating if it is changing its velocity. Since
velocity is a speed and a direction, there are only two ways
for an object to accelerate: change the speed or change
direction – or change b
If an object is speeding up, then it is accelerating and has a
positive acceleration. If it is slowing down, it is also
accelerating (or decelerating) and has a negative
acceleration. A negative acceleration is referred as
deceleration.

3. ACCELERATION
An object moving at a constant speed but rounding a curve
or corner is accelerating, too. Although its speed remains
the same, its direction changes when it rounds a curve or
corner. Hence, the velocity of the object changes.

4. ACCELERATION

5. ACCELERATION

6. ACCELERATION

7. ACCELERATION
ACTIVITY 1
1. A car starts from rest and attains a speed of 40 km/h in
20 seconds. What is its acceleration in km/h/s?
2. A cyclist going up the Kawakawa Hill at a speed of 5 m/s
slows down to 1 m/s in 8 seconds. Find his acceleration.

8. ASSIGNMENT
1. Which will have a higher speed after a minute of travel
starting from rest – a car accelerating at 2 m/s2 or a bus
accelerating at 5 m/s2?
2. Give concrete examples of accelerating objects that can
be seen in the following places:
a. on the road b. at an amusement park

9. ASSIGNMENT