Answers to the pratical questions (c) • (i) Give three examples of the use of inclined planes in everyday life. • Ramps • Stairs • Screws • (ii) Given that I is 400 N and moves a distance of 10 m while II is 100 N and moves a distance of 5 m, calculate the: • (α) work output; ×Work output = Force (II) x Distance ×Work output = 100 N x 5 m = 500 J • (β) work input; ×Work input = Force (I) x Distance ×Work input = 400 N x 10 m = 4000 J • (γ) efficiency. ×Efficiency = (Work output / Work input) x 100% ×Efficiency = (500 J / 4000 J) x 100% = 12.5% (d) • (i) Name the scientific principle being demonstrated in both A and B. • Distillation (A) • Magnetism (B) • (ii) Describe briefly the functions of each of the parts labelled II and VI. • II (Condenser): To cool the vapor back into a liquid for condensation. • VI (Magnet): To attract magnetic substances from the mixture. • (iii) Name any two types of materials that could be present in each of the set-ups labelled: • (α) III: Distillate (e.g., pure water) • (β) VII: Mixture of magnetic and non-magnetic substances. • (iv) Give the reason why the direction of water flow in A must not be reversed. • To ensure the most effective cooling of the condensing vapour. Reversing the water flow will make it harder to condense the material and it will lead to inefficiency.