EXTRA LEARNING ACTIVITY SCIENCE GRADE 8 A. Multiple Choice
1. Additive that can provide sweetness is…
a. Sodium benzoate b. Sodium cyclamate c. Sodium glutamate d. Monosodium glutamate
2. The safest colouring substances to use in food are…
a. Green CFC b. Tartrazine c. Suji leaves d. Allura red
3. Chemical substances in tea and coffee that have the ability to stimulate the central nervous system are…
a. Tar b. Nicotine c. Drugs d. Caffeine
4. The following events below that are not related to pressure is…
a. Pointed nails that are easy to pin into the board b. A small cart that is easy to push
c. A sharp knife that is easy to cut
d. Carrying a load using a small rope hurts the hands 5. Factors that can affect the magnitude of a pressure are…
a. Pressure force and mass of the object b. Pressure force and the force of gravity c. Area of the pressure field and pressure force d. Area in the pressure field and gravitational force
6. The branches of the bronchi in the respiratory system are called…
a. Alveoli b. Larynx c. Bronchioles d. Trachea
7. The structure in the larynx which functions to prevent the entry of food or drink particles into the larynx and trachea is called…
a. Cilia b. Alveoli c. Conchae d. Epiglottis
8. The main respiratory muscle and separate stomach and chest is called…
a. Diaphragm b. Bronchioles c. Epiglottis d. Trachea
9. The exchange of oxygen with carbon dioxide in the respiratory system occurs at…
a. Larynx b. Trachea c. Alveoli d. Bronchi
10. The part of kidney which carries the urine from kidney to ureter is…
a. Pelvis b. Medulla c. Cortex d. Artery
11. Look at the picture below.
The name and function of the part labelled with the letter B are…
a. Glomerulus, where the filtration process takes place
b. Proximal tubule, where the reabsorption process takes place c. Glomerulus, where the augmentation process takes place d. Proximal tubule, where the filtration process takes place
12. Albuminuria is a symptom of damage to the filtration process in the kidneys that results in urine containing…
a. Glucose and fat b. Protein and glucose c. Glycerol and fat d. Protein and albumin 13. Look at the picture below.
¾ vibration of the pendulum is shown by trajectory of the points…
a. A-B-C-B-A b. C-B-A c. B-C-B-C d. A-B-C-B
14. Sound cannot propagate through…
a. Solid b. Liquid c. Gas d. Vacuum
15. Longitudinal waves are characterized by…
a. The directions of vibration that are perpendicular to the direction of propagation b. The direction of vibration that coincides with the direction of propagation
c. Irregular vibration direction with propagation direction d. Vibrations that do not propagate
B. Essay
1. An object is located 10 cm in front of a concave mirror with a focal distance of 15 cm.
Calculate the distance of the image and where is it located?
2. An object is located 180 cm in front of a concave mirror with a radius of curvature of 120 cm. If the height of the object is 30 cm, what is the height of its image?
3. An object weighs 50 N, when weighed in water it weighs only 45 N, then the upward force pressing on the object is…
4. The cross-sectional area of the hydraulic jack is A1 = 4 m2 and A2 = 10 m2. If the input force F1 = 5 N then the maximum output force F2 is…
5. A wooden cube has a side length of 40 cm. If the mass of the wood is 8 kg and the acceleration due to gravity is 10m/s2, then calculate the pressure!
6. A wave travels at 300 m/s, its wavelength is 75 m. The frequency of the wave is…
7. If the frequency of a wave is 250 Hz, the period of the wave is…
8. The velocity of sound propagation in air is 300 m/s. If the sound of thunder is heard 2 seconds after the lightning is seen, the distance between the lightning and the observer is…