## 9th - # Energy transformation ## 20 questions # Introducing newPaper mode

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• Multiple Choice
30 seconds
1 pt

The blades of a toy helicopter spin when its circuit is connected to a battery. Which sequence below correctly identifies the energy changes taking place in the helicopter?

chemical to electrical to potential

chemical to electrical to mechanical

• Multiple Choice
1 minute
1 pt

If 200 J of energy were added to 1 g each of aluminum and copper, which would experience the LEAST temperature increase. Refer to the formula below:

$Q\ =\ mc\Delta T\ \ \ \ \ \ c\ =\ specific\ heat\ capacity$

Aluminum (c = 0.9 J/g C), because the higher the value for specific heat, the more energy is required for temperature change.

Copper (c = 0.39 J/g C), because the lower the value for specific heat, the more energy is required for temperature change.

• Multiple Choice
3 minutes
1 pt 1. A hot (100 °C) bolt with a mass of 71 grams is placed in 150 grams of cool (20 °C) water.

This diagram shows the resulting temperature changes. The specific heat of water is 4.184 J/g × °C.

Approximately how many joules of heat did the water absorb?

(Heat Lost or Gained = Mass × Specific Heat × Change in Temperature) (Q = m c ΔT)

2,510.40 J

1,118.26 J

1,506.24 J

22,191.94 J