Grade 8 Science practice

What is on the worksheet

1. A periodic wave has frequency 45 Hz and wavelength 6 m. Find its speed in m/s.

2. A sample has mass 78 g and volume 39 cm³. Calculate density in g/cm³.

3. A constant current of 14 A flows for 9 s. How much charge passes in C?

4. A model vehicle travels 182 m in 13 s at constant speed. What is its speed in m/s?

5. A constant current of 4 A flows for 118 s. How much charge passes in C?

6. Velocity changes from 22 m/s to 66 m/s in 11 s. Find average acceleration in m/s².

7. A constant current of 14 A flows for 27 s. How much charge passes in C?

8. In a simplified isotope exercise, atomic number Z = 24 and mass number A = 30. How many neutrons?

9. A constant 34 N force acts in the same direction as a 38 m displacement. Find work in J.

10. A periodic wave has frequency 27 Hz and wavelength 23 m. Find its speed in m/s.

11. In a simplified isotope exercise, atomic number Z = 29 and mass number A = 47. How many neutrons?

12. An ideal ohmic resistor of 75 Ω carries 1 A. Find the voltage across it in V.

13. Lift a 32 kg mass vertically by 20 m. Using g = 10 m/s², find the increase in gravitational potential energy in J.

14. A device transfers 391 J in 23 s. Find average power in W.

15. Cells and cell structures: which term fits this description? The net spread of particles from higher to lower concentration due to random motion.

    1. Diffusion
    2. Active transport
    3. Chloroplast
    4. Tissue

16. A constant 38 N force acts in the same direction as a 9 m displacement. Find work in J.

17. A model vehicle travels 405 m in 5 s at constant speed. What is its speed in m/s?

18. In a simplified isotope exercise, atomic number Z = 4 and mass number A = 20. How many neutrons?

19. An ideal ohmic resistor of 42 Ω carries 8 A. Find the voltage across it in V.

20. An object moves at constant velocity -27 m/s for 24 s. Find displacement in m.