Projectile Motion Quiz

Good day, students! Welcome back to Maestrang Techy's YouTube channel. Let us continue our discussion. If you haven't watched our week one video lesson about the horizontal and vertical motions of a projectile, check out the link in the description box below. We are now going to have Grade 9 Science Quarter 4 Week 2 lesson, which is all about projectile motion launched at an angle. Here's our learning objective: investigate the relationship between the angle of release and the height and range of the projectile. So, get ready to learn this lesson and keep on watching.

From the previous lesson, you were introduced to the basic concepts of projectile motion, such as trajectory and the definition of projectile motion itself. A body in projectile motion has been established to have a parabolic trajectory with horizontal and vertical components. The horizontal component of a projectile motion has the acceleration equal to zero since the velocity is constant. On the other hand, the vertical component of acceleration is constant, which is acceleration due to gravity and that is always equal to 9.8 meters per second squared. Therefore, projectile motion is the combination of horizontal motion with constant velocity and vertical motion with constant acceleration.

Take a look at this. Are you familiar with this game? Yes, baseball. This is an example of projectile motion launched at an angle. For angle launch projectile, horizontal velocity or vx is still constant while the vertical velocity can be described in three parts. First, from the picture as you observed, the projectile rises from point a to point b. The vertical velocity or vy is decreasing. This is because the direction of gravity is opposite to the projectile motion. Next, as the projectile reaches the maximum height, which is the point b, it momentarily stops, causing a vertical velocity or vy equal to zero. And third, when it returns back to the ground from point b to point c, it agrees to the direction of gravitational force, hence vertical velocity is increasing. So, when the vertical velocity of the baseball as it rises to the air decreases due to the opposing direction of gravity towards the motion, when the baseball reaches the maximum height, it momentarily stops, causing the vertical velocity to be zero. When it reaches the ground, its vertical velocity increases since the direction of the baseball's motion is the same with gravity. Take note of that, class.

Now, take a look at the variables involved in projectile launch at an angle. We have here the horizontal component and the vertical component. Next, we have the facts about projectile launched at an angle. First up, an object is projected from rest at an upward angle theta, just like this scenario. The ball started from rest where Stephen Carey is holding the ball. Second, its initial velocity can be resolved into two components, as you can see. We have the horizontal and the vertical component. Third, the horizontal velocity is constant due to gravity, a constant horizontal velocity that moves in the same direction as the launch, the acceleration of which is zero. Fourth, the amount of time the object takes to come to a stop at its highest point is the same amount of time it takes to return to where it was launched from. And lastly, the initial velocity upward will be the same magnitude as the final velocity when it returns to its original height. So, these are the facts about projectile launched at an angle.

Next, here are some of the equations that may help you solve problems involving projector launched at an angle. Let's proceed.