Projectile Motion

Aim: describe and apply the concepts of distance and displacement, speed and velocity, acceleration and energy in the context of motion in a plane, including the trajectories of projectiles in the absence of air resistance.

• Describe qualitatively the effects of air resistance on projectile motion

Terms

Term Definition SI Unit
Distance (s) Total Distance and object travels m
Displacement (s) Change in position m
Speed (v) Rate of change of distance with respect to time m/s or ms-1
Velocity (v) Rate of change of displacement with respect to time m/s or ms-1
Acceleration (a) Rate of change of velocity with respect to time m/s2 or ms-2

Calculating Projectile Motion

To calculate projectile motion, you can treat the horizontal and vertical component of motion separately and use the equations of motion to find out the answer.

Effect of air resistance

• Range is reduced
• Max height is reduced
• Angle of descent is increased

The force due to air resistance always opposes the motion and is proportional to its speed, surface area and mass.