Engineers have developed a way of charging electric cars while they are driving along the road. Coils of wire buried under the road transfer energy to the car’s battery as the car is passing over the coils.
Figure 6 shows a charging lane on a motorway. Figure 6
0 4 . 3 Suggest two advantages of using this method to charge electric cars compared with
plugging them into the mains electricity supply. 1
2
[2 marks]

The vector a? is 3.50 cm long and is directed into this page. vector b? points from the lower-right corner of this page to the upper-left corner of this page and has the components bx=-19.5 cm , by=25 cm. in the right-handed coordinate system, where the +x-axis directed to the right, the +y-axis toward the top of the page, and +z-axis out of the page, find the x-component of the vector product a? ×b? , measured in cm2.