| Date | May 2016 | Marks available | 2 | Reference code | 16M.2.HL.TZ0.1 |
| Level | Higher level | Paper | Paper 2 | Time zone | Time zone 0 |
| Command term | Determine | Question number | 1 | Adapted from | N/A |
Question
A company designs a spring system for loading ice blocks onto a truck. The ice block is placed in a holder H in front of the spring and an electric motor compresses the spring by pushing H to the left. When the spring is released the ice block is accelerated towards a
ramp ABC. When the spring is fully decompressed, the ice block loses contact with the spring at A. The mass of the ice block is 55 kg.
Assume that the surface of the ramp is frictionless and that the masses of the spring and the holder are negligible compared to the mass of the ice block.
On a particular day, the ice blocks experience a frictional force because the section of the ramp from A to B is not cleaned properly. The coefficient of dynamic friction between the ice blocks and the ramp AB is 0.030. The length of AB is 2.0 m.
Determine whether the ice blocks will be able to reach C.
Markscheme
«energy dissipated in friction =» 0.03 × 55 × 9.8 × 2.0 «= 32.3»
hence use result to show that block cannot reach C
FOR EXAMPLE
total energy at C is 670 − 32.3 − 646.8 = −9.1 J
negative value of energy means cannot reach C
Allow ECF from (a)(ii).
Allow calculation of deceleration (a = –0.29 m s–2) using coefficient of dynamic friction. Hence KE available at B = 628 J.
