Questions on Forces

Q9.

Xander sits on a mat at the top of a helter-skelter and then slides down a chute around the outside.


(a)

(i)      Name two of the forces acting on Xander as he slides from point A to point B.

any two from

    • gravity or weight
    • friction
    • air resistance or 'drag'

2 marks

(ii)     As Xander slides from point A to point B, the forces acting on him are balanced. Describe Xander's speed when the forces acting on him are balanced.

any one from

      • constant speed
      • steady speed
      • it stays the same or it does not change

1 mark

(b)     Xander goes back for a second go.  This time he sits on a smooth cushion instead of a mat. He goes much faster on the cushion.  Give the reason for this.

A cushion is smoother than a mat. There will therefore be less friction between the mat and the chute slide.

1 mark

(c)     On his third go Xander lies back on the cushion with his arms by his side.
          What happens to his speed?  Give the reason for your answer.

His speed will increase (he will go faster)because lying down he will have less air resistance opposing his motion. He will be more streamlined or aerodynamic.

2 marks
Maximum 6 marks