Answer
a.) 1260 C
b.) 1.732 kJ
Work Step by Step
Find the total charge by solving for the area under the current curve:
1.) $Q_{total} = 0.05*(6*60*60) + 0.02*(5*60*60) = 1260C$
Now find the total Energy by integrating the power of the specified times on the graph.
Setting up the integral gives:
$W = \int P*dt = \int^{5*60*60}_{0} 0.05*(\frac{0.75}{5*60*60}*t +1)*dt + \int_{5*60*60}^{10*60*60} 0.02*(\frac{0.25}{5*60*60}*t +1)*dt
= 1.732kJ $