A LEVEL PHYSICS Year 1 Projectiles A A

A LEVEL PHYSICS Year 1 Projectiles A* A B C • I can describe where else we meet projectile motion (grade b). • Be able to use the equations of uniform acceleration to solve problems that include projectile motion (grade b). B/C Target A/A* Target EP EP

Friction • A force that opposes motion, can never speed things up or start things moving and conerts kinetic energy into heat. • Contact (between solid surfaces) and fluid friction (drag, fluid resistance or air resistance). • Fluid friction: – Force depends on the viscosity (thickness) of the fluid. – Force increases as speed increases. – Force depends on shape.

Projectile motion and air resistance In most projectile questions you’ll be told to ignore air resistance but you need to know what effect it would have if you did consider it. Air resistance Drag This effects the horizontal speed of the projectile, reducing the horizontal distance it travels. If there is a vertical component of velocity, drag reduces th emaximum height the projectile will reach, and steepens the angle of descent.

Terminal Speed/Velocity

Draw a velocity-time graph and an accelerationtime graph for the flight of this parachutist.

Projectile Motion Worksheet

Answers 1. Parabolic trajectory 2. Both – horizontal velocity does not affect the vertical acceleration (due to gravity). 3. The one with the initial faster horizontal velocity (s = v x t, so if v is bigger s is bigger). 4. Horizontal velocity – remains constant throughout the trajectory and depends on the initial velocity. Vertical velocity increases under acceleration due to gravity (g). 5. - 8. Show that questions.

Prep Homework • Research two different methods for experimentally determining ‘g’ (acceleration due to gravity). • Complete the projectiles homework sheet.