The diagram shows a semi-circular track $$$A B C$$$ of radius $$$1.8 \mathrm{~m}$$$ which is fixed in a vertical plane. The points $$$A$$$ and $$$C$$$ are at the same horizontal level and the point $$$B$$$ is at the bottom of the track. The section $$$A B$$$ is smooth and the section $$$B C$$$ is rough. A small block is released from rest at $$$A$$$. Show that the speed of the block at $$$B$$$ is $$$6 \mathrm{~m} \mathrm{~s}^{-1}$$$. .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... ....................................................................................................................................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：9709_w21_qp_42 Year：2021 Question No：3(a)

Answer:

$m g \times 1.8=\frac{1}{2} m v^{2}$
Speed of block at $B=v=6 \mathrm{~ms}^{-1}$

Knowledge points:

4.5.2 understand the concepts of gravitational potential energy and kinetic energy, and use appropriate formulae

4.5.3 understand and use the relationship between the change in energy of a system and the work done by the external forces, and use in appropriate cases the principle of conservation of energy Including cases where the motion may not be linear (e.g. a child on a smooth curved ‘slide’), where only overall energy changes need to be considered.

Answer:

Knowledge points:

Solution:

Related Question