3. Sand has a low specific heat compared to air
Answer:
420J
Explanation:
Power is the time rate of change in energy. Power is the ratio of energy to time. The S.I unit of power is in watts.
Given that the flash lasts for 1/675 s, power output is 2.7 * 10⁵ W. Hence:
Power = Energy / time
Substituting:
2.7 * 10⁵ W = Energy / (1/675)
Energy = 2.7 * 10⁵ W * 1/675 = 400J
Therefore the energy emitted as light is 400J.
Since the conversion of electric energy to light is 95% efficient, hence the energy stored as electrical energy is:
Energy(capacitor) = 5% of 400J + 400J = 0.05*400 + 400
Energy(capacitor) = 420J
Answer:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
Explanation:
The graph shown in the figure is a velocity-time graph, which means that:
- On the x-axis, the time is plotted
- On the y-axis, the velocity is plotted
Therefore, this means that the object is not moving when the line is horizontal (because at that moment, the velocity is constant, so the object is not moving). This occurs in the following intervals:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
From the graph, it would be possible to infer additional information. In particular:
- The area under the graph represents the total distance covered by the object
- The slope of the graph represents the acceleration of the object
