11.3: Projectile Motion

Question 1

What is projectile motion?

Answer 1

• refers to the movement of either an object or body as they travel through the air.
• e.g. a gymnast on a vault

Question 2

What are the three factors affecting horizontal displacement?

Answer 2

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

Question 3

Horizontal displacement definition:

Answer 3

• the shortest distance from the starting point to the finishing point in a line parallel to the ground

Question 4

How does the angle of release affect horizontal displacement of a projectile?

Answer 4

• when both release height and the landing height are equal, the optimum angle of release in 45 degrees. E.g. long jumper
• if the release height is below the landing height, optimum angle of release needs to be greater than 45 degrees. E.g. shooting in basketball.
• if release height is greater than the landing height, the optimal angle of release is below 45 degrees. E.g. this can be seen in the flight of the shot put where hand (release) is much higher than landing point (ground)

Question 5

Optimum angle of release definition:

Answer 5

• angle between the horizontal and direction of projectile at release.

Question 6

Optimal angle of release - elite shot putter:

Answer 6

• anywhere between 26-38 degrees.
• keeping the angle smaller means more speed can be generated as shot is released.
• however optimal angle also depends on size, strength and through technique of athlete.

Question 7

How does speed of release affect horizontal displacement of projectile?

Answer 7

• the greater the velocity of a projectile, the greater the horizontal displacement.
• e.g. 5£3 speed of the rotation across circle ensures that the shot leaves the hand at maximum velocity so a greater horizontal displacement can be achieved

Question 8

How does height of release affect horizontal displacement of a projectile?

Answer 8

• the greater the height also increases horizontal displacement
• the shot putter should try to release the shot are the highest point possible above the ground to gain maximum HD. This is due to gravity constantly acting on the mass of the shot put.

Question 9

What is a parabola?

Answer 9

• a curve with matching left and right hand sides

Question 10

What factors affecting the flight paths of different projectiles?

Answer 10

• weight
• air resistance

Question 11

How do weight and air resistance affect paths of projectiles?

Answer 11

• projectiles with a large weight force have a small resistance force and follow a true parabolic flight path. E.g. shot put.
• the longer the flight path the longer air resistance can affect a projectile. Projectiles with lower mass the effects of AR result in distorted parabola. E.g. badminton shuttlecock due to being lighter and an unusual shape increasing air resistance.

Question 12

Horizontal component definition

Answer 12

• the horizontal motion of an object.

Question 13

Vertical component definition:

Answer 13

• the upward motion of an object.