Learning Area

Science

Grade Level

Quarter

4th

Date

I. LESSON TITLE

Forces and Motion

II. MOST ESSENTIAL LEARNING

COMPETENCIES (MELCs)

Describe the horizontal and vertical motions of a projectile.

III. CONTENT/CORE CONTENT

Projectile Motion

IV. LEARNING PHASES AND LEARNING ACTIVITIES

I. Introduction (Time Frame: Day 1)

Uniformly Accelerated Motion

A body is said to have uniform acceleration if it maintains a constant change in its velocity in each time interval along a straight

line. This can be along the horizontal (rectilinear) or along the vertical (free fall). For rectilinear motion, let us take a track and

field runner competing in the 100-m run as an example. If the runner’s positions are taken at equal time intervals and the

change in position for each time interval is increasing, then, the runner is moving faster and faster. This means that the runner is

accelerating.

The pull of gravity acts on all objects. So, when you drop something or even when you throw something up, it will go down.

Things thrown upward always fall at a constant acceleration which has a magnitude of 9.8 m/s2. This means that the velocity

of an object changes by 9.8 m/s every second of fall. Consider a ball thrown upward. As the ball goes up, it decelerates until

it stops momentarily and changes direction. That means, it reaches its maximum height before it starts to fall back to the point

where it was thrown, and its speed will be equal to the speed at which it was thrown. Note that the magnitudes of the two

velocities are equal, but they have opposite directions – velocity is upward when it was thrown, but downward when it returns.

Free-fall is an example of uniformly accelerated motion, with its acceleration being -9.8 m/s2, negative because it is downward.

The equations for Uniformly Accelerated Motion (UAM) are:

𝑣𝑓= 𝑣𝑖+𝑎𝑡 where: 𝑣𝑓 = final velocity/speed

𝑑 = 𝑣𝑖𝑡 + 1

2𝑎𝑡2 𝑣𝑖 = initial velocity/speed

𝑣𝑓

2= 𝑣𝑖

2+ 2𝑎𝑑 𝑎 = constant acceleration

𝑑 = (𝑣𝑖+ 𝑣𝑓

2)𝑡 or 𝑑 =𝑣𝑡 𝑡 = time

𝑑 = distance/displacement

𝑣 = average speed/velocity

D. Development (Time Frame: Day 2)

Motion in Two Dimensions

Many of the games you play and sporting events you join/officiate in during PE classes involve flying objects or balls. Have you

noticed the curved paths they make in mid-air? This curve is what naturally happens when an object, called a projectile, moves

in two dimensions –having both horizontal and vertical motion components, acted by gravity only. In physics this is called

projectile motion. Not only balls fly when in projectile motion. Have you noticed that in many sports and games, players come

“flying” too? Understanding motion in two-dimensions will help you apply the physics of sports and enhance game events

experiences.

Projectile motion is a combination of uniform motion along the horizontal and the motion of a freely falling body along the

vertical. It is an instance of uniformly accelerated motion in two-dimensions. The moving body is called a projectile, the curved

path it travels is known as the trajectory and the horizontal distance it covers is called range. The horizontal and vertical motions

of a projectile are completely independent of each other.

Therefore, horizontal and vertical motion can be treated separately.

Q4 Science 9 Week 1 - Hope this helps with your studies and submissions!

Science Technology and Society (STS)

ICCT Colleges Foundation

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