Forces: Projectile motion

Question 1

are forces:
A) scalars
B) vectors

Answer 1

Vectors

Question 2

Name 2 horizontal forces

Answer 2

• friction

- Air resistance

Question 3

What does the size of the arrow mean on a free body diagram?

Answer 3

The magnitude/size of the force

Question 4

What are balanced forces?

Answer 4

Vertical and horizontal forces are equal to each other

Question 5

What are unbalanced forces?

Answer 5

One of the forces is unequal (larger or smaller than the other)

Question 6

What is meant by the net force?

Answer 6

the summary of all the forces in action

Question 7

Describe a vector diagram for long jump

Answer 7

• large internal muscular force from the legs to produce a big action force
• more vertical force than horizontal force produced by the muscles
• results in a high trajectory

Question 8

What is gravity?
What way does gravity act?
How does it affect a performer?

Answer 8

• gravity is the force pulling the performer to the ground
• Acts vertically
• This speeds up the falling of the performer
• works in the same direction as motion

Question 9

What is air resistance? (AR)
What way does this force act?
How does it affect a performer?

Answer 9

• AR is the force applied by the air on bodies that are moving through it
• acts both horizontally and vertically
• It affects the performer because it slows the performer down
• acts in the opposite direction to motion

Question 10

What is friction?
What way does this force act?
How does it affect a performer?

Answer 10

• friction is when two surface slide against each other
• Acts horizontally
• prevents performer slipping and sliding

Question 11

How can we increase friction?

Answer 11

• rougher surfaces
• increase the mass of performer
• increase surface area

Question 12

What are the 2 types of friction?

Answer 12

• static - friction before an object starts to slide

- sliding - friction when an object is moving

Question 13

What is reaction force?

What way does this force act?

Answer 13

• occurs when you push off a surface
• acts horizontally and vertically
• acts in the same direction as the motion

Question 14

What is muscular action force?

How does this force act?

Answer 14

• causes motion as it acts internally

- acts horizontally and vertically

Question 15

what are the factors affecting gravity?

Answer 15

mass of body

Question 16

what are the factors affecting air resistance?

Answer 16

• the cross sectional area of the body

- speed of the body

Question 17

what are the factors affecting friction?

Answer 17

roughness of a surface

Question 18

What are the factors affecting reaction force and muscular action?

Answer 18

Physiology e.g muscle innervation, muscle fibre types, motor neuron recruitment etc

Question 19

What is projectile motion?

Answer 19

movement of an object/human body as it travels through the air

Question 20

What is horizontal displacement?

Answer 20

Shortest distance from start point to finish point in a line parallel to the ground.

Question 21

What are the factors affecting projectile motion?

Answer 21

• angle of release
• hight of release
• speed or release

Question 22

Angle of release AO1

Answer 22

• ensures body travels as far as possible

- Optimum angle of release is 45 degrees, both hight of release and landing release are equal.

Question 23

What happens when the release hight below the landing hight?

Answer 23

• angle of release has to be greater than 45 degrees

Question 24

what happens when the release hight is higher than landing hight?

Answer 24

• angle of release less than 45 degrees

Question 25

Speed of release AO1

Answer 25

• greater the release velocity, the greater the horizontal displacement

Question 26

Height of release AO1

Answer 26

• Greater the release hight increases horizontal displacement

Question 27

How does the height of release affect a shot put?

Answer 27

• Gravity constantly acting on the shot put

Performer should release at the highest point possible to gain max displacement.

Question 28

What are factors affecting flight paths of projectiles?

Answer 28

• weight
• AR
  These are crucial in deciding if the projectile has a true parabola or a distorted parabola

Question 29

What is true of parabolas and and large weight forces

Answer 29

These projectiles which have a large weight force have small air resistance and follow true parabolic flight

Question 30

How would speed of release affect a shot put?

Answer 30

the speed across the circle (preparation phase) ensures the shot put leaves with max velocity, causing greater horizontal displacement.

Question 31

give an example where the release height is is below the landing hight

Answer 31

basketball - shooting a hoop if the ring is the landing height

Question 32

give an example where the release hight is above the landing hight

Answer 32

in shot put where the hand is the point of release which is above the landing point (ground)

Question 33

What happens when a projectile has lighter mass in terms of parabola?

Answer 33

• AR means that it deviates from a true parabolic flight path to a deviated parabolic flight path

Question 34

How would parabola be applied to a shuttlecock?

Answer 34

• Shuttlecock has lighter mass
• ” unusual shape which increases AR
• starts off with high velocity via the force of the racket
• velocity decreases as AR reduces