3a The power (in watts) from an engine is represented by the equation: P = 100t1.4 + 6t , where t is the time in seconds. Draw the graph that represents power against time for this engine. Show the area on the graph which represents the energy produced between 5 s and 15 s. Show, using summation, how you would gain an approximation for the energy. Using integration, evaluate the exact energy between 5 s and 15 s. 3b Part of a machine moves with a velocity given by the expression: V = 7tz +0.8t mm/s. Calculate the displacement over the first 5 seconds of motion