M1 – Projectiles Summary M1 – Projectiles Summary Modelling assumptions: No air resistance– gravity is the only force acting and the ground is a level plane Modelling assumptions: No air resistance– gravity is the only force acting and the ground is a level plane Throughout the flight of a projectile Horizontal acceleration = 0 ms-2 and vertical acceleration = g ms-2 Since the acceleration is constant the suvat equations apply in both the horizontal and vertical directions To calculate time of flight use vertical displacement = 0 m. If the projectile is released from the same height as it lands, its path is symmetrical. At its maximum height the vertical velocity = 0 ms-1. (When the particle is released from the same height as it lands, this is halfway through the flight.) Range is the horizontal distance travelled. To find the range calculate horizontal displacement at the time when the particle lands. Horizontal velocity is constant throughout the flight. To find the speed and direction of the projectile at any time use Pythagoras and trigonometry on the components of v Remember, at the maximum height the vertical component of velocity is zero. This is the time when the projectile has its least speed. If the object is released from a height h the same motion will occur but take the height of release is the origin. (When the projectile lands on the ground the vertical displacement = h.) Throughout the flight of a projectile Horizontal acceleration = 0 ms-2 and vertical acceleration = g ms-2 Since the acceleration is constant the suvat equations apply in both the horizontal and vertical directions To calculate time of flight use vertical displacement = 0 m. If the projectile is released from the same height as it lands, its path is symmetrical. At its maximum height the vertical velocity = 0 ms-1. (When the particle is released from the same height as it lands, this is halfway through the flight.) Range is the horizontal distance travelled. To find the range calculate horizontal displacement at the time when the particle lands. Horizontal velocity is constant throughout the flight. To find the speed and direction of the projectile at any time use Pythagoras and trigonometry on the components of v Remember, at the maximum height the vertical component of velocity is zero. This is the time when the projectile has its least speed. If the object is released from a height h the same motion will occur but take the height of release is the origin. (When the projectile lands on the ground the vertical displacement = h.) When the two components are combined these result in the following formulae: a = gj v = ucosI + (usin gt)j r = utcosi + (utsin 12 gt2 + h)j When the two components are combined these result in the following formulae: a = gj v = ucosI + (usin gt)j r = utcosi + (utsin 12 gt2 + h)j where u is the initial speed, is the angle of projection and h is the height of release. where u is the initial speed, is the angle of projection and h is the height of release.