Physics (Essay) Paper 2 WASSCE (PC), 2022

Question 8

 

(a)        (i) what are crystalline substances?
(ii)        state two examples each of:
(α)       crystalline substance;
(β)       amorphous substance.
                                                                                   
(b)  (i)  A body was placed at different points on the earth’s surface and was observed that its weight varies at different points. State three reasons for the observation

(ii)        A car travels from a starting point, P, and moves x km northwards, 40 km eastwards, 30 km southwards and then gets to a point m where it turns 400 west of south at a distance of 50 km from its starting point, P.

(α)       Sketch a diagram showing the directions of motion of the car at each  stage. (β) Calculate the value of x

(c)        State three characteristics of pressure in fluids.

Observation

 

The expected response:
(a)  (i)   Crystalline substances         
       They are substances whose ions/atoms/molecules are arranged in a regularly repeated pattern.  [2 marks]

(ii) (α) Examples of crystalline substances                                                    
-           Sodium chloride/common salt/table salt
-           Zinc chloride
-           Copper sulphate
-           Ice
-           Zinc sulphate
-           Sodium sulphate
-           Diamond
-           Graphite
-           Sodium sulphate
-           Sodium nitrate

                                                                                                                                                               
(β)        Examples of Amorphous substances
-           Glass
-           Wood
-           Paper
-           Asbestos
-           Plastic
-           Rubber
-           Coal

            (b)       (i) Reasons for observation
-           Rotation of the Earth
-           Shape of the Earth/The Earth is not a perfect sphere
-           Variation in acceleration due to gravity

(c)        Characteristics of Pressure in Fluids
-           It is independent of the area of the containing vessel.
-           It increases with depth.
-           It depends on the density of fluid.
-           It is equal at all points at the same level.
-           It is transmitted equally in all directions at a given level.
-           It is dependent on acceleration due to gravity.