Topic 1A Motion

Answer → B

this is projectile motion, which can be separated into two independent components:
horizontal and vertical motion.

horizentally no forces are acting on the ball, so a = 0
so only suitable equation, [s = v x t]

[CP 1: Determine the acceleration of a freely-falling object]

(b) Explain the motion of the unicycle. Your answer should make reference to all of the forces acting on the unicycle. (2marks)

• W is the weight of man and R is the reaction force from ground
  
  

• since weight and reaction force are different types of forces, weight is non contact NRF is contact
  
  (R and W are on the same object as i.e man + unicyle = object, its considered as one as they are basically joined)
  
  

• so it cannot be newtons third law pair forces
  
  
  (b)
  - horizentally there is constant speed so the forward force from friction = drag
  - RF acting in the vertical direction is 0, so 0 acceleration in the vertical direction
  
  NOTE:
  usually when body is traveling horizentally, it’s vertically at rest
  
  similarly if a body was vertically traveling it is horizentally at rest
  [but in projectile motion body moves both ways]

as yk reaction prevents an object from passing through it,

i.e hinge’s reaction prevents flagpole passing through it

watch this :) —>