Projectiles & Assumptions

Question 1

Projectile Assumptions (7)

Answer 1

• No air resistance
• Constant gravity (9.8)
• Constant horizontal velocity
• No curvature in earth
• Constant initial velocity
• Both launch & impact points are the same height
• Motion is symmetrical (parabola)

Question 2

Formula: Maximum Height

Answer 2

u^2 x sin2(theater) / 2g

Question 3

Formula: Range

Answer 3

u^2 x sin2(theater) / g

Question 4

Formula: Time - Maximum Height

Answer 4

u x sin(theater) / g

Question 5

Formula: Time - Flight

Answer 5

2u x sin(theater) / g

Question 6

Expand: sin2(theater)

Answer 6

2sin(theater)cos(theater)

Question 7

“Gravity doesn’t affect horizontal velocity.”

Why is this? & State the column vector for this statement.

Answer 7

( 0 )
(- g )

Question 8

“Speed is the magnitude of velocity vector.”

Show this mathematically.

Answer 8

v | = (square root) vx^2 + vy^2

Pythagoras

Question 9

What is:

horizontal component, ux

vertical component, uy

Answer 9

• ux = U cosθ
• uy = U sinθ