Projectile Motion Flashcards
state what it is meant by the key term - ‘projectile motion’
projectile motion is the motion observed when bodies are projected into the air and are under the influence of gravity (and air resistance) only
what is the value of acceleration due to gravity on earth ?
- 9.81 m/s^2
state what it is meant by the key term - ‘projectile’
a projectile is a body that is undergoing projectile motion
what can a projectile be in S+E ?
in S+E, a projectile can be an object (eg - equipment), a body, or both (a system)
state what it is meant by the key term - ‘gravity’
gravity is the attraction influence (force) that pulls objects towards the earth’s surface
state what it is meant by the key term - ‘air resistance’
air resistance is a frictional force that occurs when air pushes over the surface of a body
state an expansionary fact about ‘gravity’
gravity uniformly accelerates a projectile towards the earth’s surface at - 9.81 m/s^2
state 2 expansionary facts about ‘air resistance’
- limits the motion of a projectile
2. compared to gravity, air resistance is often minimal/negligible, so is often neglected
state what it is meant by the key term - ‘trajectory’
trajectory - the flight path of an object through the air
state what it is meant by the key term - ‘parabola’
parabola - the trajectory follows a ‘parabolic’ curve shape that is symmetrical about its apex
state what it is meant by the key term - ‘apex’
apex - the highest point reached by a projectile
state what it is meant by the key term - ‘range’
range - the horizontal displacement of a projectile
state the 3 determinants of projectile motion
- projection angle
- projection velocity
- projection height
state the 2 influences imposed by the projection angle
- the angle at release determines the shape of the trajectory, all other factors being equal
- projectile angle influences the relative magnitude of the vertical and horizontal components
a positive angle is > 0’, state 2 facts
- between 0-90 degrees = oblique trajectory
2. parabolic shape, symmetrical about the apex
0 degrees = horizontal trajectory (horizontal with the ground). state 2 facts
- if no projection height, there will be no flight
2. if projection height, trajectory resembles one half of a parabola
90 degrees, vertical trajectory. state 1 fact
projectile follows the flight path up and down with no range
a negative angle is < 90 degrees, below horizontal. state 1 fact
not considered for projectile motion
state what it is meant by the key term - ‘projectile velocity’
projectile velocity determines the height and range of a projectile, all other things being equal
what determines the height and time of flight ?
vertical velocity (Vy) determines the height and time of flight
what is the formula for Vy ?
Vy = V x sin(θ)
what is the formula for ‘time of flight’ ?
Δt = 2 x ((Vy,f - Vy,i) / a)
state the 2 formulae to work out maximum height
displacement (s) = (Vy,i x Δt) + 1/2 x a x Δt
displacement (s) = (Vy,f^2 - Vy,i^2) / (2 x a)
what does horizontal velocity determine ?
horizontal velocity determines the range
