FM - Unit 3

Question 1

xuvat

Answer 1

v = u + at
v^2 = u^2 + 2ax
x = (u+v)/2 t
x = ut + 1/2 at^2

Question 2

Behaviour After Circular Motion Ceases

Answer 2

The body is subject to gravity and behaves as a
projectile

Question 3

For Body Free Falling Into Circular Motion

Answer 3

Model as a particle until point when in circular motion using xuvat

Question 4

Why Is It Unnecessary To Model Collisions Using Spheres?

Answer 4

Velocity is parallel to line along spheres’ centers

Radii are equal

Question 5

How Should You Give The Answer If Asked For Speed Direction In Collisions?

Answer 5

In terms of initial motion direction (opposite or same)

Question 6

Show That Body WIll Remain In Contact

Answer 6

Find reaction forces at initial and final points and show that they are both more than 0 AND that the final R is greater than the initial R. (implies contact wasn’t lost inbetween)

Question 7

Under What Conditions Does A Rod Have Thrust vs Tension?

Answer 7

Thrust - T < 0

Tension - T > 0

Given that you’ve defined T as pointing towards the center

A rod has tension when it is being pulled, thrust when it is being compressed (can’t tell logically in circular motion)

Question 8

Contact Conditions For Always In Contact

Answer 8

String & free body - T > 0 at peak

Rod & attached body - v > 0 at peak

Question 9

Range of Theta

Answer 9

Always within 0 to 360

Question 10

Cosine Rule, Sine Rule

Answer 10

a^2 = b^2 + c^2 - 2abcos0

sinA / a = sinB / b = sinC / c