3 2 1 1 2 4 3 -1 x 10,000 5,000 20 M Time (min) y t

3 2 1 1 2 4 3 -1 x 10,000 5,000 20 M Time (min) y t

3 2 1 1 2 4 3 -1 x 10,000 5,000 20 M Time (min) y t

Example 5 Power Delivered by a Battery The power that a battery supplies to an apparatus such as a laptop depends on the internal resistance of the battery. For a battery of voltage V and internal resistance r, the total power delivered to an apparatus of resistance R (Figure 2) is (a) Calculate dP/dR, assuming that V and r are constants

Example 5 Power Delivered by a Battery The power that a battery supplies to an apparatus such as a laptop depends on the internal resistance of the battery. For a battery of voltage V and internal resistance r, the total power delivered to an apparatus of resistance R (Figure 2) is (a) Calculate dP/dR, assuming that V and r are constants (b) Where, in the graph of P versus R, is the tangent line horizontal?