11. Projectile Motion

Question 1

Why is the path of projectile motion curved?

Answer 1

The horizontal component stays constant whilst the vertical component is affected by the acceleration due to gravity

Question 2

Describe the method of finding how long it takes for an object in projectile motion to fall to the ground from a height

Answer 2

Use the vertical motion which has a constant acceleration under gravity and use s = 1/2 gt^2 to find t

Question 3

Describe the method of finding how far an object in projectile motion goes in the horizontal direction

Answer 3

Since the horizontal motion is not affected by gravity or any force it moves at a constant speed so you can use velocity = displacement / time

Question 4

Describe the method used when projectile motion happens at an angle

Answer 4

1. Resolve initial velocity into horizontal and vertical components
2. Use the vertical component to work out how long it is in the air and/or how high it goes
3. Use the horizontal component to work out how far it goes in the horizontal direction while it is in the air

Question 5

What does air resistance cause?

Answer 5

A drag force that acts in the opposite direction to motion and affects the trajectory of the projectile

Question 6

What does the drag force in the horizontal direction cause?

Answer 6

The horizontal distance that the object travels reduces because the horizontal speed is negatively affected

Question 7

What does the drag force in the vertical direction cause?

Answer 7

The vertical component will be reduced so the maximum height that the object can reach reduces, steepening the angle of descent