W5 - Collisions, Momentum & Impulse

Question 1

What are the types of collisions?

Answer 1

Elastic

Inelastic

Question 2

Define elastic collisions

Answer 2

KE of system is conserved.

Very uncommon in sport.

Question 3

Define inelastic collisions

Answer 3

KE is transferred to another form of energy.

Question 4

How is momentum calculated?

Answer 4

Mass (kg) x velocity (m/s)

P = m x v

Question 5

What is the only way in which the momentum of a system will change + isn’t conserved?

Answer 5

If a resultant force acts on it

Question 6

How is the total momentum of a system (i.e 2 objects) calculated?

Answer 6

Total momentum = (mass1 x velocity1) + (mass2 x velocity2)

Question 7

What equation is used to calculate the velocity of 2 players after collision?

Answer 7

= (Total momentum of system) / (total mass of system)

Question 8

How is change in momentum calculated?

Answer 8

Mass (kg) x change in velocity (m/s)

Question 9

Which newtons law is momentum linked to?

Answer 9

2nd

Question 10

Equation w/:

Force (N)
Change in momentum
Change in Time

Answer 10

Force = (Change in M / Change in T)

Question 11

What is the rate of change of momentum of an object directly proportional to?

Answer 11

To the resultant force applied + is in the direction of that resultant force

Question 12

What is impulse equal to?

Answer 12

Change in momentum

Question 13

How is impulse calculated?

Answer 13

Force (N) x time (s)

Question 14

How can we increase the impulse?

Answer 14

⬆️ force

⬆️ time over which force is applied

Question 15

When looking at a horizontal force (from ground reaction force) against time graph for a runner and assessing impulse, which part of the graph displays the impulse?

Answer 15

Area under force-time curve

Question 16

In a graph showing horizontal force against time, also showing impulse as the area under the force-time curve, what can you say if these areas are equal when above and below the x axis?

Answer 16

Equal -ive + +ive impulse = overall 0 change in velocity = constant speed

Question 17

When running, which of the horizontal impulses acts as a braking impulse, slowing you down?

Answer 17

The negative horizontal impulse

Question 18

How is total net impulse over a stride calculated?

Answer 18

Positive impulse + negative impulse

Question 19

When running, what is the positive horizontal impulse?

Answer 19

A propulsive impulse to speed us up

Question 20

How is net horizontal impulse calculated (a.k.a change in momentum)?

Answer 20

Mass (kg) x change in velocity

Question 21

What can and what can’t pressure plates measure?

Answer 21

Yes = Pressure patterns under the foot over time

No = Quantify horizontal components of the applied force.