Answer Key: Last Paper

37(c)
Water is absorbed/ removed from the undigested food.
1/2m
* Water is sucked out (0m)
38(a)
10 km
1m

38(b)
As the number of bacteria increases, it uses up oxygen to decompose, so amount of dissolved oxygen decreases making most of the fish die.

1m

39(a)
Beaker 2. They can be dissolved in water(1m) and they are not a magnetic material (1m).

2m

39(b)
S/ The magnetic material (1/2 m). Place a magnet near the surface of the dry tray until it attracts substance S. (1/2 m)

1m

40(a)
The purpose of the experiment is to find out the thermal conductivity of the three materials./ which material is the best conductor of heat.

1 m
*which material is a good conductor ( 0m)
40(b)
Copper is the best/fastest heat conductor as the time taken to reach the final temperature is the shortest.

1m

41(a)

Weight hung(g)

0
10
20
30
40

Extension of the Spring (cm)
0
5
10
15
20
1 m
½ m for each correct answer
41(b)

1m
* Points marked but no line drawn (0m)
41(c)
The heavier/greater the mass of the weights hung on the spring, the longer/greater the extension of the spring. OR
The lesser the mass of the weights hung on the spring, the lesser the extension of the spring.

1m

41(d)
Gravity/ Gravitational force
1m

42(a)
Distance the object moved from Position X.

1m
*Distance the object moved (1/2 m)
42(b)
The more the elastic band is stretched, the further the object will move from Position X. OR
The lesser the elastic band is stretched, the lesser the distance the object will move from Position X.

1m

42(c)
(Elastic) potential energy is changed to kinetic energy.

1 m

43(a)
Car C as the difference between the braking distance on a raining day and sunny day is the most / longest.

1 m

43(b)
Use tyres with more groove / pattern/ thread. OR
Change tyres to rougher tyres/ tyres with more friction.

1m
*Change new tyres (0m)
*Wheels(0m)
43(c)
Less friction / frictional force between the tyre and the road. OR
The rain water acts as lubricant between the tyre and the road.

1m

44(a)
I will put object P into beaker X carefully and object Q into beaker Y carefully. (1/2 m) I will compare the new water levels.(1/2 m)
1m


44(b)
The new water level in beaker X is higher than the new water level in beaker Y.
1m