projectile motion

Question 1

factors affecting the distance travelled by a projectile

Answer 1

• height of release
• speed of release
• angle of release

Question 2

height of release -

Answer 2

• 45o is the optimal angle of release if the releasing + landing height are equal
• if release height is above the landing height = less than 45o
  e.g. shot put, javelin
  = already has increased flight time due to increased height of release
• greater than 45o is optimal angle of release if release height is below the landing height
  e.g. bunker shot in golf
  = needs an increased flight time to overcome the obstacle

Question 3

speed of release -

Answer 3

• the greater the force applied through a projectile, the further it will travel (Newton’s 2nd law of motion)

Question 4

angle of release -

Answer 4

• 90o = projectile will accelerate vertically upwards + come straight back down travelling 0m
• > 45o = projectile reaches peak height too quickly + rapidly returns to ground
• 45o = optimal angle ot maximise horizontal distance
• <45o = projectile doesn’t achieve sufficient height to maximise flight time

e..g golf, javelin, ball sports, ski jumping etc..

Question 5

parabolic - (shotput)

Answer 5

• if weight is the dominant force + air resistance is very small = parabolic flight occurs

e.g. shot put has a very high mass
- travels through the air at a low velocity
- w/ a small frontal cross-sectional area + smooth surface
= air resistance negligible
- flight path = parabolic shape, symmetrical about its highest point

Question 6

non-parabolic - (badminton shuttlecock)

Answer 6

• if air resistance is the dominant force + weight is very small = non-parabolic shape occurs

e.g. shuttlecock has a very low mass
- travels at high velocities
- w/ a relatively uneven surface
= increases air resistance
- flight path = non-parabolic shape asymmetrical about its highest point

Question 7

bernoulli’s principle

Answer 7

• the creation of an additional upwards lift force on a projectile
• due to a pressure difference of air travelling around a projectile
• the air will travel faster over the top of a projectile (LOW pressure, HIGH velocity)
• the air will travel travel slower under the projectile (HIGH pressure, LOW velocity)’

Question 8

Magnus force

Answer 8

applying spin to a projectile through the application of an eccentric force

Question 9

types of spin

Answer 9

• top, side, back spin in tennis + table tennis
• side spin in football
• hook + slice in golf