# Hosted by 8 th Grade Science - PowerPoint PPT Presentation

Hosted by 8 th Grade Science

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Hosted by 8 th Grade Science

## Hosted by 8 th Grade Science

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##### Presentation Transcript

1. Spring EOST Review Jeopardy Hosted by 8th Grade Science

2. Work, Power and Machines Waves and Sound Electricity and Magnetism Energy and Heat 100 100 100 100 200 200 200 200 300 300 300 300 400 400 400 400 500 500 500 500

3. Row 1, Col 1 To make work easier. What is the purpose of a simple machine?

4. 1,2 Mechanical Energy This is the energy of a moving windmill.

5. 1,3 A mechanical wave requires a medium, an electromagnetic wave does not. What is the difference between a mechanical and an electromagnetic wave?

6. 1,4 A radio wave has a longer wavelength and lower frequency than a gamma ray but both travel at the same speed. This is the difference between a radio and a gamma ray in terms of frequency, wavelength and speed.

7. 2,1 The machine could change the direction of the input force, increase the output force by reducing the input distance or increase the output distance by reducing the input force. What are the 3 ways that a machine can make work easier?

8. 2,2 PE = W x H PE = 50 X 5 PE = 250 J How much potential energy does a 50 N box have if it is sitting 5 m above the floor have?

9. 2,3 Refraction This property explains why a light wave bends when it enters a new medium.

10. 2,4 Off When a circuit is open are the lights on or off?

11. 3,1 None – in order for work to be done the object must move in the direction of the force. How much work does a man do when he pulls on a heavy cabinet with a force of 50 N and the cabinet still does not move?

12. 3,2 heat This is the movement of thermal energy from one object to another.

13. 3,3 Why does a red transparent water bottle appear red? Because only red light is being transmitted, all other colors are being absorbed.

14. 3,4 The brightness will remain the same but the battery will drain faster. What will happen to the circuit below if a bulb is added?

15. 4,1 It allows you to use less force over a greater distance How does a doorknob (wheel and axle) make work easier?

16. 4,2 The pot because thermal energy is total kinetic energy and the pot has more mass so it will have more total energy. You have a pot and bowl of soup at the same temperature. Which has more thermal energy? Why?

17. 4,3 The amplitude becomes higher and the frequency decreases. A high pitch, soft sound suddenly becomes loud and low pitch. Explain how the properties of the wave must have changed.

18. 4,4 Friction – rubbing a balloon in your hair Induction – the now charged balloon can cause charges to rearrange within another object without direct contact. Give an example of charging by friction and induction.

19. 5,1 W = f x d W = (100 x 9.8) x 0.5 W = 490 J How much work does a man do if he lifts a 100 kg box 0.5 meters off of the table?

20. 5,2 KE = ½ mv2 KE = ½(240)(10)2 KE = 12,000 J A 240 kg skier flies down the hill at 10 m/s. What is her kinetic energy?

21. 5,3 F = S/W F = 21/3 F = 7 Hz What is the frequency of a wave that has a wavelength of 3 meters, amplitude of 2 meters and a speed of 21 m/s.?

22. 5,4 A solenoid, add an iron core or more coils. What is the device above called, how could it be strengthened?