7.8 Projectile motion 2

Question 1

Describe the drag force (resistive force) that acts on an object in projectile motion

Answer 1

• acts in the opposite direction to the direction of motion of the projectile and it increases as the projectiles speed increases
• has a horizontal component that reduces both the horizontal speed of the projectile and its range
• reduces the maximum height of the projectile if its initial direction is above the horizontal an makes its descent steeper than its ascent

Question 2

What partially causes the drag force on an object in projectile motion?

Answer 2

The friction between the layers of air near the projectiles surface where air flows over the surface.

Question 3

How can the shape of an object create a lift force amidst projectile motion?

Answer 3

This happens if the shape of the projectile causes the air to flow faster over the top of the object than underneath it.

As a result, the pressure of the air on the top surface is less than that on the bottom surface.

This pressure difference causes a lift force on the object.